THE  ESSENTIALS   OF  PSYCHOLOGY 


THE  MACMILLAN  COMPANY 

HEW  YORK    •    BOSTON   •    CHICAGO  •    DALLAS 
ATLANTA  •    SAN  FRANCISCO 

MACMILLAN  &  CO.,  LIMITED 

LONDON  •    BOMBAY  •    CALCUTTA 
MELBOURNE 

THE  MACMILLAN  CO.  OF  CANADA,  LTD. 

TORONTO 


THE   ESSENTIALS   OF 
PSYCHOLOGY 


BY 


W.    B.    PILLSBURY 

TOR  OF  THE  PSYCHOLOGICAL   LABOR; 

!t  OF  PSYCHOLOGY,  UNIVERSITY  OF  I 
AUTHOR  OF  "THE  FUNDAMENTALS  OF  PSYCHOLOGY" 


DIRECTOR  OF  THE  PSYCHOLOGICAL  LABORATORY 
PROFESSOR  OF   PSYCHOLOGY,   UNIVERSITY   OF   MICHIGAN 


REVISED  EDITION 


THE   MACMILLAN   COMPANY 

192] 

411  rig/itt  rearvtd 


PRINTED  IN  THE  UNITED  STATES  OF  AMERICA 


COPYRIGHT,  191 1  AND  1920, 

By  THE    MACMILLAN  COMPANY. 

Revised  Edition. 


Set  up  and  electrotyped.     Published  January,  1920. 


TO 
E.  C.  R 


2056326 


PREFACE   TO  THE   FIRST  EDITION 

THE  aim  of  this  volume  is  to  present  clearly  the  ac- 
cepted facts  of  psychology.  Throughout,  emphasis  has 
been  placed  upon  fact  rather  than  theory.  Where 
theories  conflict,  the  better  one  has  been  chosen,  the 
others  merely  neglected.  This  may  seem  dogmatic  in 
places,  but  in  a  text  dogmatism  is  preferable  to  con- 
fusion. The  point  of  view  is  on  the  whole  functional ; 
more  attention  is  given  to  what  mind  does  than  to  what 
it  is.  With  this  goes  an  emphasis  upon  the  outward 
manifestations  of  consciousness  and  upon  the  behaviour 
of  others  to  the  subordination  of  the  individual  con- 
sciousness. Nevertheless,  use  is  made  of  the  results 
of  structural  psychology  wherever  they  throw  light 
upon  function  or  are  interesting  for  themselves.  The 
position,  it  is  hoped,  combines  the  advantages  of  the 
rival  schools. 

The  content  of  a  text-book  in  psychology  is  suffi- 
ciently agreed  upon  to  require  no  comment.  The 
general  practice  has  been  followed  of  introducing  a 
brief  exposition  of  the  nervous  system  and  its  function. 
This  is  done  with  a  full  appreciation  that  it  is  no  part 
of  the  task  of  the  psychologist  to  teach  neurology,  but 
with  the  conviction  that  the  beginning  student  in  psy- 
chology is  not  likely  to  have  acquired  the  knowledge 
elsewhere.  In  this  treatment  as  little  detail  of  structure 


V1U  PREFACE 

has  been  given  as  is  compatible  with  an  understanding 
of  function.  Large  use  has  been  made  of  the  hypothe- 
sis of  the  synapse.  Its  convenience  in  explaining  habit 
and  association  outweighs  any  scruples  about  its  final 
position  in  physiology.  For  the  rest,  I  have  deviated 
from  traditional  usage  only  in  introducing  rather  more 
of  the  results  of  recent  experiment.  A  body  of  knowl- 
edge has  been  developing  in  connection  with  memory 
and  action  that  seems  ripe  for  embodiment  in  a  text. 
Similar  considerations  have  led  to  the  introduction  of 
chapters  on  fatigue  and  on  the  transfer  of  training. 

The  general  arrangement  followed  is  relatively  novel. 
It  consists  in  first  developing  a  few  simple  principles 
and  then  making  frequent  application  of  them  to  the 
more  complicated  processes.  Sensation,  habit,  reten- 
tion, and  selection  or  control  are  fundamental  and 
appear  repeatedly  in  mental  operations  of  all  kinds. 
When  they  are  once  understood,  it  is  only  necessary 
to  develop  their  applications  and  interconnections  to 
master  the  more  developed  operations.  The  method 
involves  much  repetition,  but  not  more  than  the  expe- 
rience of  the  writer  has  proved  necessary.  What  is  not 
understood  in  one  connection  is  made  clear  by  the  next 
application. 

My  obligations  to  psychological  writers  are  so  gen- 
eral and  so  apparent  as  to  need  no  special  acknowledg- 
ment. Dr.  Rowe  of  the  Central  Normal  School,  Mt. 
Pleasant,  Michigan,  has  read  the  manuscript  and  made 
many  suggestions.  Thanks  are  due  also  to  my  colleague, 
Dr.  Shepard,  for  help  at  many  points.  I  owe  most 
to  my  wife,  who  has  given  constant  advice  in  matters 


PREFACE  IX 

of  expression,  and  has  been  of  great  service  in  the  me- 
chanical preparation  of  the  book. 

I  desire  also  to  express  my  thanks  to  authors  and 
publishers  for  permission  to  reproduce  illustrations. 
I  am  indebted  to  The  W.  B.  Saunders  Company  and 
Professor  Howell  for  figures  from  'The  Text-book  of 
Physiology'  and  the  'American  Text-book  of  Physi- 
ology'; to  Dr.  L.  F.  Barker  for  figures  from  his  'Ner- 
vous System';  to  Henry  Holt  and  Company  and 
Professor  Angell  for  cuts  from  his  'Psychology';  to 
Houghton  MifHin  Company  and  Professor  Jastrow  for 
figures  from  '  Fact  and  Fable  in  Psychology ' ;  to  The 
Macmillan  Company  and  Professors  Titchener  and 
Calkins,  respectively,  for  figures  from  '  A  Text-book 
of  Psychology'  and  'A  First  Book  of  Psychology'; 
to  Professor  Swift  for  a  Curve  of  Learning,  and  to 
Professor  von  Frey  for  permission  to  adapt  his  Tem- 
perature Scale. 

ANN  ARBOR,  MICH., 
April  25, 1911. 


PREFACE   TO  THE   SECOND   EDITION 

I  HAVE  made  numerous  changes  in  this  edition  to 
bring  it  abreast  of  the  most  recent  results  in  the  science, 
to  improve  the  expression,  and  to  increase  its  value  for 
class-room  use.  A  new  chapter  has  been  added  on 
Types  of  Mind  which  introduces  some  of  the  more 
general  results  of  mental  testing,  the  chapter  on  Emotion 
has  been  largely  rewritten,  much  new  matter  has  been 
added  to  the  chapter  on  Memory,  and  new  paragraphs 
have  been  added  or  old  ones  rewritten  in  most  of  the 
chapters.  For  the  convenience  of  the  teacher  and  of 
the  student  who  desires  to  review  for  himself,  the 
questions  and  exercises  have  been  revised  and  con- 
siderably extended.  Although  each  teacher  will  desire 
to  make  a  list  for  himself,  these  will,  it  is  hoped,  be  useful 
as  a  basis. 

It  is  with  pleasure  that  I  acknowledge  numerous 
suggestions  from  many  colleagues  which  have  aided 
much  in  the  present  revision  and  in  minor  revisions  in 
earlier  reprintings.  I  wish  that  I  could  mention  all 
by  name,  but  the  list  is  too  formidable.  I  am  indebted 
to  my  colleagues  Professor  Adams  and  Dr.  Griffitts 
and  to  Professor  Ha'yes  of  Mount  Holyoke  for  help 
with  the  questions.  Professor  Whipple  has  read  the 
chapter  on  Types  of  Mind  and  made  valuable  sug- 
gestions. I  desire  now  to  thank  all  for  their  help  and 


W.   B.   PILLSBURY. 

ANN  ARBOR. 
November  i,  1919. 


TABLE   OF   CONTENTS 

CHAPTER  PAGE 

I.    INTRODUCTION i 

II.    THE  NERVOUS  SYSTEM 17 

III.  NEURAL  ACTION  IN  RELATION  TO  CONSCIOUSNESS 

AND  BEHAVIOUR 49 

IV.  SENSATION 64 

V.  SELECTION  AND  CONTROL  —  ATTENTION         .        .112 

VI.  RETENTION  AND  ASSOCIATION         .        .        .        .141 

VII.    PERCEPTION 169 

VIII.    MEMORY  AND  IMAGINATION 204 

IX.    REASONING      .  - 241 

X.    INSTINCT 267 

XI.    FEELING 288 

XII.    THE  EMOTIONS ^04 

XIII.  ACTION  AND  WILL 326 

XIV.  WORK,  FATIGUE,  AND  SLEEP 358 

XV.  INTERRELATIONS  OF  MENTAL  FUNCTIONS       .        .374 

XVI.    THE  TYPES  OF  MIND 388 

XVII.    THE  SELF ,408 


xiii 


ESSENTIALS  OF  PSYCHOLOGY 


CHAPTER  I 
INTRODUCTION 

Psychology  the  Science  of  Behaviour.  —  Psychology 
is  defined  traditionally  as  the  science  of  mind.  This 
is  the  translation  of  the  two  Greek  words  from  which 
'  psychology  '  is  compounded.  The  definition  is  now 
open  to  many  objections.  The  most  important  of  these 
is  that  the  word  '  mind  '  has  in  the  course  of  long  use 
taken  on  many  meanings  and  implications  which  do  not 
concern  psychology  as  a  science.  Various  terms  have 
been  suggested  to  avoid  these  objections.  Psychology 
has  been  denned  as  the  '  science  of  consciousness/  or 
as  the  '  science  of  experience  subjectively  regarded.' 
Each  definition  has  advantages,  but  no  one  so  far  sug- 
gested is  free  from  objection.  It  is  most  satisfactory 
to  give  up  the  attempt  to  find  a  single  word  that  will 
designate  the  facts  covered  by  psychology,  and  to  in- 
dicate the  actual  phenomena  that  it  studies,  —  the 
evidences  of  mind.  First  of  these  is  behaviour.  We 
distinguish  a  man  in  the  full  possession  of  his  senses 
from  an  imbecile  by  the  character  of  his  acts.  We 
measure  the  intelligence  of  an  animal  by  its  accom- 
plishments. Mind  is  known  from  the  activities  of  the 


2  THE   ESSENTIALS   OF   PSYCHOLOGY 

organism.  Psychology  may  be  most  satisfactorily  de- 
fined as  the  science  of  behaviour.  We  shall  discuss 
human  behaviour. 

This  definition  makes  it  possible  to  treat  man  as 
objectively  as  any  physical  phenomenon.  It  considers 
only  what  he  does.  Viewed  in  this  way  the  end  of  our 
science  is  to  understand  human  action.  The  practical 
end  is  to  determine  upon  what  human  capacity  depends 
and,  in  the  light  of  this  knowledge,  to  discover  means 
of  increasing  man's  efficiency.  In  many  fields  of  in- 
dustry it  is  becoming  more  and  more  evident  that  an 
understanding  of  the  laws  of  human  efficiency  is  quite 
as  important  as  a  knowledge  of  mechanical  laws,  that 
it  is  quite  as  important  to  know  what  a  man  can  do  in 
a  given  time  and  how  he  should  work  to  obtain  the  best 
results  as  to  know  the  laws  for  the  production  of  energy 
in  boiler  and  engine.  In  fact,  it  is  appreciated  in 
many  industries  that  further  progress  must  wait 
upon  increased  knowledge  of  the  human  instrument. 
Psychology  is  concerned  only  indirectly  with  these  prac- 
tical problems.  Science  always  endeavours  to  under- 
stand the  laws  of  nature  for  themselves  and  is  indifferent 
to  the  applications  that  may  be  made  of  them.  Psy- 
chology is  interested  in  the  conditions  of  learning  and 
forgetting,  of  imagining  and  reasoning,  and  in  the 
methods  of  acquiring  skill  in  various  activities  without 
any  thought  of  the  use  that  may  be  made  of  the  knowl- 
edge. It  is  probable,  however,  that  all  suggestions  for 
improving  the  efficiency  of  individuals  must  be  based 
upon  these  laws.  Indeed,  many  rules  have  already 
been  developed  from  psychological  experiments  and 


DEFINITIONS     OF    PSYCHOLOGY  3 

more  are  foreshadowed  in  the  general  principles  now 
established. 

If  psychology  is  to  be  defined  as  the  science  of  human 
behaviour,  the  term  '  behaviour  '  must  be  used  in  the 
very  widest  sense.  It  must  include  everything  from  the 
simplest  movements  of  walking  or  of  fingering  the  pen 
to  the  activities  involved  in  swaying  an  audience  by 
speech  or  in  carrying  to  completion  some  great  engineer- 
ing work.  Certain  of  the  very  simplest  acts,  such  as 
winking  and  other  reflexes,  are  fairly  within  the  range 
of  physiology.  But  even  these  must  be  taken  into 
consideration  by  psychology,  because  the  most  com- 
plicated act  can  be  understood  only  when  analysed  into 
its  components  which  are  reflexes  or  closely  related  to 
reflexes.  Even  the  simplest  forms  of  behaviour  must 
be  studied  by  the  psychologist  if  he  is  to  know  the  laws 
that  govern  the  more  complicated  forms.  No  form  of 
human  behaviour,  from  the  simplest  to  the  most  com- 
plex, falls  outside  of  the  province  of  psychology.  As  a 
science  our  knowledge  of  human  behaviour  must  be 
organised  and  referred  to  a  system  of  general  principles. 
A  science  of  human  behaviour  cannot  be  limited  to  a 
series  of  aphorisms  or  chance  observations  about  man. 
'  Perseverance  wins  success  '  is  related  to  the  psychology 
of  conduct  in  very  much  the  same  way  that  '  an  east 
wind  brings  rain '  is  related  to  the  science  of  meteor- 
ology. Each  statement  embodies  the  results  of  nu- 
merous observations,  but  it  has  no  close  connection 
with  other  facts  or  general  laws.  In  a  science  these 
observations  must  be  related  to  other  bits  of  knowledge 
and  the  whole  organised  into  a  consistent  system  that 


4  THE  ESSENTIALS   OF   PSYCHOLOGY 

shall  harmonise  with  the  results  of  other  sciences. 
Scientific  laws  are  based  on  carefully  chosen  data  and 
in  consequence  possess  wide  validity  and  are  not  likely 
to  be  vitiated  by  popular  prejudice  or  ill-founded  tradi- 
tion. They  give  each  particular  fact  a  perspective  and 
make  it  easy  to  recall  and  to  use  each  new  observation. 
Study  of  Behaviour  Involves  Consciousness.  —  To 
define  psychology  as  the  study  of  behaviour  does  not 
imply,  as  has  been  asserted  at  times,  that  we  can  neglect 
consciousness.  For  most  individuals,  consciousness  is 
as  much  a  fact  as  the  existence  of  any  external  object. 
When  a  man  acts  he  is  aware  that  he  is  acting  and  also 
aware  of  the  stimuli  that  produce  the  act.  This  aware- 
ness is  what  we  mean  by  consciousness.  While  the 
reader  might  at  this  moment  be  observed  by  a  friend 
to  hold  the  book  and  move  the  eyes  by  jerks  across  the 
page  with  an  occasional  frown  as  a  difficult  sentence  is 
met,  the  reader  himself  is  aware  of  the  sense  of  the  ma- 
terial, and  thinks  in  some  part  the  ideas  intended  by  the 
writer.  The  observer  appreciates  the  behaviour,  the 
reader,  consciousness.  In  this  case  behaviour  is  the 
immediate  outcome  of  consciousness  and  can  only  be 
understood  through  it.  The  frown  is  explained  by  the 
hesitation  in  getting  the  meaning  of  a  sentence,  and 
that  is  most  evident  to  the  reader.  While  many  kinds 
of  activity  are  best  known  from  the  inside,  others  may 
be  as  well  known  from  the  outside.  Thus  the  capacity 
of  an  individual  for  assimilating  the  material  of  this 
chapter  may  be  determined  better  by  the  instructor 
who  assigns  it  and  quizzes  on  it  than  by  the  student. 
This  is  particularly  true  if  the  reading  is  done  under 


CONSCIOUSNESS    AND    BEHAVIOUR  5 

the  observation  of  the  teacher.  The  differences  in 
capacity  to  learn  and  repeat  can  be  explained  only 
through  long  study  of  the  individual  in  the  light  of 
earlier  training  and  habits  of  work. 

Consciousness  an  End.  —  Psychology,  then,  must 
study  consciousness  as  well  as  behaviour.  This  is 
necessary  first  because  much  of  behaviour  is  known 
only  from  the  report  of  the  actor  and  many  of  the 
conditions  of  behaviour  can  be  studied  only  through 
consciousness.  This  holds  particularly  of  the  more 
complicated  acts,  of  the  lines  of  conduct  determined 
by  remote  events  in  the  life  of  the  individual.  In  the 
second  place,  consciousness  is  worth  understanding  for 
itself.  For  the  individual  man,  be  he  nai've  or  erudite, 
nothing  is  so  interesting  as  the  working  of  his  own  mind. 
Much  of  the  consciousness  of  an  individual  is  followed 
by  relatively  slight  movements,  while  the  consciousness 
itself  is  a  matter  of  great  moment.  Had  it  no  other 
value,  to  understand  consciousness  would  be  sufficient 
to  warrant  the  existence  of  the  science.  Consciousness 
is  at  once  an  important  means  of  understanding  be- 
haviour and  an  interesting  object  of  investigation  for 
itself.  Consciousness  and  behaviour  are  closely  re- 
lated ;  consciousness  in  others  is  known  only  through 
behaviour,  behaviour  in  ourselves  and  ultimately  in 
others  is  known  only  through  consciousness.  If  one 
is  made  the  end,  the  other  must  be  the  means ;  if  either 
is  understood  in  its  completeness,  the  other  will  also  be 
known.  They  are  the  inside  and  outside  of  the  same 
organism.  Even  if  in  the  present  stage  of  development 
of  the  science  it  seems  best  to  subordinate  consciousness 


6  THE   ESSENTIALS   OF   PSYCHOLOGY 

to  behaviour  in  the  definition  of  psychology,  for  the  sake 
of  escaping  ambiguity,  we  cannot  eliminate  conscious- 
ness from  description  and  explanation.  Psychology  is 
the  science  of  behaviour,  but  behaviour  must  be  studied 
both  through  the  consciousness  of  the  actor  and  by 
observation  of  the  acts  of  others. 

Mind,  Consciousness,  and  Mental  Process.  —  Before 
attempting  any  discussion  of  mental  states  it  is  necessary 
to  define  certain  of  the  terms  that  are  to  be  used.  Viewed 
from  within,  psychology  seeks  to  explain  the  experiences 
of  the  individual  as  they  run  their  course,  —  to  under- 
stand the  various  perceptions,  memories,  imaginings, 
and  so  on  which  together  constitute  the  mental  life. 
Any  one  of  the  states  that  may  be  regarded  as  detached 
from  the  mass  for  separate  consideration  is  designated  a 
mental  process.  Your  idea  of  this  book  as  you  read  it 
is  a  mental  process,  your  memory  of  reading  the  book 
yesterday  or  of  the  assignment  for  study  is  a  mental 
process,  as  is  the  flitting  thought  that  you  would  much 
rather  be  out  for  a  walk  than  reading.  Consciousness  is 
the  term  technically  used  to  designate  the  sum  total  of 
mental  processes  at  any  moment.  Thus,  the  perception 
of  the  book,  the  background  of  tactual  and  organic  sen- 
sations that  are  receiving  no  particular  attention  at  the 
moment,  the  vague  emotional  dissatisfaction  that  you 
are  kept  indoors  on  a  pleasant  day,  and  many  other 
more  or  less  definite  mental  processes  combine  to  con- 
stitute your  consciousness  at  this  moment.  Mind  is 
the  word  that  designates  the  entire  series  of  conscious 
states  of  an  individual  from  birth  to  death.  It  is  the 
most  inclusive  of  the  series  of  terms  and  covers  all 


INTROSPECTION  7 

processes,  active  and  passive.  Experience  includes 
practically  the  same  mass  of  states,  but  it  is  a  little 
more  passive  in  its  implications.  All  of  these  terms 
apply  to  the  description  of  behaviour  as  observed  from 
within,  the  mental  antecedents  and  accompaniments  of 
behaviour.  The  description  of  behaviour  as  it  presents 
itself  to  the  outside  observer  needs  only  the  vocabulary 
of  popular  speech  and  requires  no  preliminary  com- 
ment or  definition. 

The  Methods  of  Psychology.  —  As  has  been  said,  be- 
haviour can  be  studied  in  two  ways :  by  observation  of 
another's  acts  and  by  observation  of  one's  own  conscious 
states.  Observation  of  another,  or  what  in  psychology  is 
known  as  observation,  requires  no  special  comment  as  a 
method.  In  all  essential  respects  it  follows  the  rules  of 
observation  common  to  all  of  the  sciences.  Self-obser- 
vation, known  technically  as  introspection,  seems  at 
first  sight  to  offer  more  difficulties  and  to  require  more 
safeguards.  The  question  has  been  raised  whether  in- 
trospection is  possible  at  all.  The  doubt  arises  from  the 
assumption  that  the  very  observation  of  a  mental  state 
changes  that  state.  One  does  not  have  the  same  mental 
state  when  questioning  how  one  knows  that  the  approach- 
ing footsteps  are  Smith's,  as  when  one  interprets  the 
sounds  to  mean  that  Smith  is  coming.  One  cannot  at 
the  same  moment  wonder  what  one  is  doing  and  do  it  to 
the  best  advantage.  This  objection  proves  to  be  less 
serious  in  practice  than  in  theory.  All  mental  states  per- 
sist for  a  little  time  unchanged  and  it  is  possible  to  ob- 
serve them  during  this  persistence.  One  does  not  ob- 
serve the  mental  state  at  the  time  it  is  happening,  but 


8  THE   ESSENTIALS   OF  PSYCHOLOGY 

examines  it  a  moment  later  in  memory.  Observation 
in  memory  is  accurate  and  does  not  alter  the  process 
investigated.  Observation  in  any  natural  science  re- 
quires the  same  reliance  on  momentary  memory.  One 
cannot  at  the  same  time  make  an  observation  and 
record  it.  If  one  tried,  mistakes  would  be  made.  A 
thermometer  reading,  e.g.  is  taken  and  held  in  memory 
until  recorded,  and  then  still  later  it  is  interpreted  or 
used  in  the  explanation  of  related  facts.  Introspection 
is  no  more  difficult  or  uncertain  than  is  observation  of 
external  phenomena.  ' 

Experiment.  —  Within  the  last  generation  methods 
have  been  developed  by  which  both  introspection  and 
observation  can  be  carried  on  under  experimental 
conditions  and  with  the  aid  of  instruments  of  precision. 
Experiment  makes  it  possible  to  control  accurately  the 
conditions  and  antecedents  of  mental  operations.  It 
is  possible  now  to  remove  from  distracting  stimuli  the 
individual  who  is  introspecting  or  being  observed,  to 
measure  accurately  the  stimuli  that  are  permitted  to 
affect  him,  and  to  record  his  responses.  It  is  a  com- 
monplace that  a  man  who  is  embarrassed  will  blush. 
Delicate  physiological  instruments  used  in  the  psycho- 
logical laboratory  show  that  the  blush  is  only  a  height- 
ened effect  of  the  changes  in  circulation  that  take  place 
in  all  parts  of  the  body  in  connection  with  almost  all 
mental  processes.  Similarly  it  was  first  observed  with 
the  unaided  eye  that  the  eyes  move  by  jumps  during 
reading.  Later  it  was  found  possible  to  photograph  the 
movements  of  the  eyes,  and  these  results  brought  out 
important  laws  that  could  not  have  been  known  other- 


EXPERIMENT  IN  PSYCHOLOGY  9 

wise.  Introspection  has  been  aided  principally  by  re- 
cording the  times  that  elapse  between  different  parts  of 
a  mental  operation.  The  times  required  have  been 
combined  and  the  results  emphasised  relations  that 
were  unnoticed  in  introspection.  While  experiment  is 
only  a  means  of  increasing  the  accuracy  of  observation 
and  introspection,  it  has  through  its  wide  application 
made  possible  important  advances  in  nearly  every  field 
of  psychology.  To  its  great  benefit  psychology  has 
become  an  experimental  science. 

But  momentary  introspection  and  observation  com- 
bined; even  with  all  the  help  that  may  be  had  from 
experiment,  do  not  exhaustively  explain  behaviour  or 
consciousness.  The  observer  sees  the  occasion  for 
action  and  notes  the  response ;  the  actor  sees  the  object 
and  feels  the  response,  but  neither  knows  what  happens 
in  between  nor  appreciates  fully  the  conditions  of  the 
act.  For  example,  a  wasp  approaches,  the  man  draws 
back  or  strikes.  The  observer  notes  the  occasion  for 
the  movement  and  the  movement  itself,  but  nothing 
more.  The  man  attacked  sees  the  wasp  and  knows 
that  he  is  moving  or  has  moved,  but  nothing  more. 
Neither  can  know  why  the  movement  takes  place. 
One  sees  the  stimulus  vanish  into  the  physical  organ- 
ism and  movement  result ;  the  other  sees  the  insect, 
moves,  and  all  the  time  is  perturbed  by  an  emotion, 
but  neither  can  absolutely  foresee  the  act,  neither 
knows  why  it  comes.  These  more  fundamental  ex- 
planations may  be  supplied  in  part  on  the  basis  of 
present  knowledge.  Two  elements  must  be  taken  into 
consideration  in  the  interpretation,  —  the  character 


10  THE   ESSENTIALS   OF   PSYCHOLOGY 

and  nature  of  the  action  of  the  nervous  system,  and 
the  past  life  and  native  endowment  of  the  individual. 
One  can  understand  what  intervenes  between  the  ex- 
citation and  the  movement  only  if  one  can  trace  the 
course  of  the  impulse  through  the  nervous  system.  The 
earlier  history  of  the  individual  and  of  the  race  also 
plays  a  very  large  part  in  the  determination  of  all  sorts 
of  behaviour.  The  man's  responses  will  differ  accord- 
ing to  the  amount  and  nature  of  his  experience  with 
wasps.  The  influence  of  earlier  experiences  can  be 
traced  in  many  more  subtle  ways  in  the  interpretation 
of  any  mental  phenomenon.  Both  the  nervous  system 
and  the  effects  of  earlier  life  upon  the  acts  of  the  in- 
dividual can  be  known  only  through  observation  and 
introspection,  controlled  and  recorded,  together  with 
much  experiment  and  reflection  upon  the  connections 
of  present  with  past  activities.  Human  behaviour, 
then,  can  be  understood  by  careful,  long-continued 
observation  of  man  in  action  from  the  inside  and  from 
the  outside,  and  by  relating  the  results  of  these  observa-- 
tions  to  the  earlier  experiences  of  the  individual  and  to 
the  facts  concerning  the  nature  and  action  of  the  nervous 
system  established  by  the  anatomist  and  the  physiologist. 
Relation  of  Psychology  to  Other  Sciences.  —  The  re- 
lations of  psychology  to  the  other  sciences  are  particu- 
larly close  and  important.  The  biological  sciences  shade 
over  into  psychology  so  gradually  that  it  is  not  always 
possible  to  decide  whether  a  problem  belongs  to  psy- 
chology or  to  one  of  the  biological  sciences.  The 
sciences  that  explain  the  nature  and  action  of  the  hu- 
man body,  the  sciences  of  anatomy  and  physiology, 


PSYCHOLOGY   AND    BIOLOGY  II 

merge  gradually  into  psychology.  One  can  under- 
stand behaviour  only  if  one  knows  something  of  the 
living  organism,  of  the  sense  organs  that  receive  the 
impression  from  without,  of  the  muscles  that  produce 
the  actions,  and  of  the  nervous  system  that  connects 
them.  From  the  outside  one  can  understand  man's 
behaviour  most  fully  and  easily  by  comparing  it  with 
the  behaviour  of  animals  and  tracing  the  gradual  de- 
velopment of  man's  action  in  connection  with  th*; 
simpler  forms  of  animal  behaviour.  Experimental 
biology  gradually  shades  over  into  experimental  psy- 
chology. The  biologist  has  recently  been  devoting 
himself  very  largely  to  the  problems  of  animal  be- 
haviour. The  light  cast  upon  human  conduct  by  these 
experiments  is  only  less  important  than  that  cast  upon 
the  actions  of  animals  themselves.  Still  more  general 
results  of  biological  science  have  been  profoundly  im- 
portant for  the  explanation  of  human  consciousness. 
The  very  general  acceptance  in  recent  times  of  the 
doctrine  of  evolution  has  forced  us  to  read  the  story 
of  mind  in  the  light  of  the  development  of  the  human 
organism  from  the  lower  forms  of  life.  The  result  is  a 
very  much  fuller  understanding  of  many  of  the  more 
fundamental  phases  of  human  activity.  All  of  the 
physical  sciences  furnish  some  material  for  the  psy- 
chologist, since  the  sense  processes  can  be  understood 
only  in  connection  with  the  physical  forces  that  act 
upon  the  organism. 

The  Social  Sciences.  —  In  addition  to  the  sciences 
from  which  it  receives  material  and  methods,  psychology 
has  come  into  a  position  where  it  may  offer  help  to 


12  THE   ESSENTIALS   OF   PSYCHOLOGY 

many  sciences.  If  psychology  can  give  information 
concerning  human  behaviour,  it  is  evident  that  all  the 
human  and  social  sciences  may  look  to  it  for  aid  in  the 
solution  of  their  problems.  Sociology,  or  the  study  of 
man  in  the  group,  evidently  must  found  its  results 
upon  a  study  of  the  individual.  In  less  degree,  history, 
when  it  seeks  to  trace  connections  between  its  observed 
facts,  must  look  to  psychology  for  its  fundamental 
principles.  Economics,  too,  works  with  psychological 
materials.  Its  fundamental  problems  are  essentially 
psychological.  Values  and  human  needs  are  largely 
mental.  It  must  be  said,  however,  that  psychology  is 
least  well  developed  in  the  fields  where  it  would  be  most 
helpful  to  the  historian  and  to  the  economist.  Last  of 
all,  the  relations  of  psychology  to  philosophy  are  very 
numerous  and  are  those  of  mutual  helpfulness.  Psy- 
chology was  the  last  of  the  sciences  to  separate  from 
philosophy,  the  parent  of  all  of  the  sciences,  and  the 
bond  is  still  very  close.  The  history  of  psychology  is 
still  very  largely  a  part  of  the  history  of  philosophy. 
The  results  of  psychology  constitute  much  of  the  foun- 
dation of  philosophy,  and  on  the  other  hand  philosophy 
supplies  the  psychologist  with  general  principles  and 
sets  very  many  of  his  problems  for  him. 

Practical  Applications.  —  Of  the  immediately  prac- 
tical subjects,  education  has  probably  made  the  largest 
demands  upon  the  results  of  our  science.  Learning  and 
teaching  are  both  psychological  operations.  When  any 
real  attempt  to  understand  either  is  made,  education 
becomes  an  application  of  psychology.  This  is  more 
and  more  appreciated  in  the  modern  schools,  and  in 


APPLICATIONS    OF   PSYCHOLOGY  13 

them  psychology  and  education  are  coming  closer  and 
closer  together.  The  psychologist  is  paying  more  atten- 
tion to  the  problems  of  the  educator,  and  the  modern 
educational  theorists  are  making  more  use  of  the  results 
of  psychological  investigations.  But  the  applications 
of  psychology  need  not  be  confined  to  education.  With 
the  advance  of  knowledge  all  who  have  to  deal  with 
man  will  look  to  the  psychologist  to  increase  the  knowl- 
edge that  may  be  put  at  his  disposal.  The  physician 
and  the  lawyer,  the  advertiser  and  the  clergyman,  are 
all  dealing  in  one  way  or  another  with  psychological 
problems.  To  the  physician  and  the  advertiser  psy- 
chology has  already  given  appreciable  aid  and  it  should 
be  in  a  position  at  no  distant  day  to  offer  help  to  the 
others.  Too  much  of  practical  value  is  not  to  be  ex- 
pected from  the  science,  however.  In  all  of  these  fields 
there  is  a  great  difference  between  principles  and  prac- 
tice. Often  the  rules  that  grow  from  daily  practice 
are  in  advance  of  scientific  principles.  Science  serves 
but  to  explain  the  truth  of  the  practical  precept.  Theory 
does  not  always  lag  behind,  and  one  can  already  see 
places  in  which  psychological  results  point  the  way  to 
improvement  in  practice.  As  a  rule,  however,  all  of 
the  arts  are  more  grateful  for  confirmation  of  the 
established  custom  than  for  the  suggestion  of  improve- 
ments. This  incomplete  list  of  the  relations  of  psy- 
chology may  suffice  to  indicate  how  closely  psychology 
is  bound  up  with  other  fields  of  human  knowledge.  Any 
science  that  tells  us  any  thing  of  the  nature  of  the  physical 
universe  or  of  the  nature  of  the  living  organism  will  throw 
some  light  upon  the  problems  of  psychology.  On  the 


14  THE   ESSENTIALS   OF   PSYCHOLOGY 

other  hand,  any  science  that  deals  in  any  way  with 
human  conduct,  or  that  is  dependent  in  any  way  upon 
human  capacity  (and  what  science  is  not?),  can  draw 
with  profit  upon  the  results  of  psychology.  Either  as 
creditors  or  debtors,  all  the  sciences  stand  in  some  rela- 
tion to  psychology,  the  science  of  human  behaviour. 

Divisions  of  Psychology.  —  Each  of  the  sciences  that 
furnish  material  for  psychology  has  given  rise  to  a  differ- 
ent sort  of  psychology,  or  at  least  to  a  different  name 
for  a  psychological  work.  Psychophysics  grew  out  of 
an  attempt  by  Fechner  to  determine  the  quantitative 
relations  between  the  physical  stimulus  and  the  in- 
tensity of  the  mental  state.  Physiological  psychology 
is  the  name  Wundt  gives  to  his  work,  that  has  for  its 
primary  object  the  explanation  of  the  relation  between 
mental  states  and  the  bodily  organism.  Each  of  these 
treatments  has  grown  beyond  its  original  scope  to  cover 
the  entire  field  of  psychology.  The  name  now  indicates 
nothing  more  than  the  attitude  that  is  taken  toward  the 
subject.  Other  branches  of  the  subject  are  named 
from  the  phase  of  behaviour  that  is  discussed.  Genetic 
psychology  treats  of  the  development  of  behaviour.  The 
behaviour  of  animals  has  given  rise  to  a  flourishing  science 
and  in  the  last  few  years  has  made  much  progress.  Child 
study  has  made  numerous  contributions  to  the  more 
theoretical  problems.  Each  has  thrown  some  light  upon 
the  nature  of  adult  human  behaviour,  as  well  as  collected 
many  facts  in  its  own  field.  Abnormal  psychology,  the 
study  of  abnormal  and  imperfect  individuals,  has  also 
been  a  rich  field  for  the  psychologist  and  has  given  many 
important  results.  Each  of  these  partial  sciences  may 


BRANCHES   OF   PSYCHOLOGY  1$ 

be  considered  by  us  only  so  far  as  it  throws  light  on  the 
behaviour  of  the  adult  normal  man.  A  few  years  ago 
it  was  customary  to  classify  psychological  systems  ac- 
cording to  the  methods  of  investigation.  There  was  a 
rational  psychology,  an  empirical  psychology,  an  intro- 
spective psychology,  and  an  experimental  psychology. 
Now  it  is  seen  that  no  science  can  be  developed  by  one 
of  these  methods  alone,  and  all  are  used  by  any  psy- 
chologist worthy  of  the  name.  At  the  most  it  can  now 
be  said  that  there  is  an  empirical  and  a  rational  method 
in  psychology,  a  method  of  introspection  and  a  method 
of  observation,  both  aided  by  experiment.  The  results 
of  each  method  should  be  the  same  if  the  methods  are 
adequate.  And  as  a  matter  of  fact  the  results  are  the 
same  although  one  method  may  be  adequate  for  one 
problem,  another  for  another.  All  the  so-called  branches 
of  psychology,  then,  are  closely  related  to  the  central 
science  and  at  the  most  designate  merely  different  fields 
for  observation,  or  the  preference  of  writers  for  different 
methods. 

Summary.  —  Our  problem  is  to  understand  behaviour, 
and  to  investigate  consciousness  as  the  immediate  ante- 
cedent and  condition  of  behaviour.  To  understand 
either  consciousness  or  behaviour  it  is  necessary  to 
know  something  of  the  character  and  action  of  the 
nervous  system.  As  has  been  said,  all  knowledge  of 
the  world  comes  to  consciousness  through  the  nervous 
system  and  all  expressions  of  consciousness  in  actiop 
are  rendered  possible  by  the  nervous  system.  This  i? 
not  psychology  but  is  a  necessary  prerequisite  for  psy 
chology.  The  psychological  inquiry  proper  begins  with 


1 6  THE   ESSENTIALS   OF   PSYCHOLOGY 

an  analysis  of  the  elements  of  behaviour  and  of  con- 
sciousness, both  structural  and  functional;  it  involves 
a  study  of  how  these  elements  interact  and  unite  in 
the  constitution  and  control  of  the  more  complicated 
activities.  The  various  partial  problems  will  be  taken 
up  in  the  order  named :  first,  a  brief  statement  of  the 
facts  of  nervous  physiology  that  have  a  bearing  upon 
psychology ;  second,  an  analysis  of  the  facts  of  con- 
sciousness and  behaviour  to  discover  the  elementary 
components,  and  third,  a  study  of  the  more  complicated 
activities  in  the  light  of  these  simplest  forms. 

QUESTIONS 

1.  What  are  the  evidences  of  mind  (a)  in  an  animal,  (6)  in 
another  man,  (c)  in  yourself? 

2.  How  far  does  knowledge  of  behaviour  involve  consciousness  ? 

3.  What  is  a  science  ?    Is  it  possible  to  have  a  science  of  mind  ? 
of  behaviour? 

4.  What  is  the  method  of  introspecting?    What  question  of 
its  accuracy  has  been  raised  ?    How  can  the  objection  be  met  ? 

5.  What  is  a  psychological  experiment  ?    Illustrate  its  applica- 
tion to  observation  and  to  introspection. 

6.  What  sciences  aid  most  in  the  solution  of  psychological 
problems  ? 

7.  Enumerate  some  of  the  divisions  of  psychology.    What  is 
the  basis  of  division  in  each  case  ? 

REFERENCES 

ANGELL  :  Chapters  in  Modern  Psychology. 
TITCHENER  :  Textbook  of  Psychology.    Chapter  I. 


O  CHAPTER  II 

THE  NERVOUS  SYSTEM 

BEHAVIOUR  must  be  explained  in  large  part  by  the 
action  of  the  nervous  system.  It  does  not  follow  that 
the  operation  of  the  brain  or  of  the  nervous  system  is 
open  to  observation.  On  the  contrary,  one  knows 
nothing  directly  of  the  nerves  or  of  nerve-cells.  Only 
consciousness  and  behaviour  are  known.  The  parts  that 
act  are  altogether  hidden,  the  effects  alone  are  known. 
So  completely  is  this  true  that  even  Aristotle,  the  most 
acute  observer  of  antiquity,  had  no  suspicion  that  the 
brain  had  much  to  do  with  mental  processes.  He  held 
that  the  brain  was  merely  a  gland  for  the  secretion  of 
tears  and  that  its  only  function  in  thinking  was  to  cool 
the  animal  spirits  that  originated  hi  the  heart  and  cir- 
culated through  the  brain. 

Dependence  of  Consciousness  on  the  Nervous  System. 
—  If  one  cannot  observe  the  workings  of  the  nervous 
system  directly,  one  may  ask  what  right  we  have  to 
assert  that  consciousness  is  related  to  it.  Two  facts 
bear  most  strongly  in  proof  of  the  relation.  The  first  is 
that  behaviour  increases  in  complexity  with  increase  in 
the  complexity  of  the  nervous  system.  In  the  rudi- 
mentary organisms  no  nervous  system  can  be  distin- 
guished. The  same  protoplasm  that  cares  for  the 
nutrition  of  the  body  also  receives  the  stimulus  and 
c  17 


i8 


THE  ESSENTIALS  OF  PSYCHOLOGY 


contracts.  All  parts  are  alike  and  each  does  all  things 
necessary  to  its  own  welfare.  The  movements  are 
correspondingly  simple  and  the  organism  poorly  ad- 


FIG.  i.  —  Shows  the  development  of  pyramidal  cells  from  the  cerebrum  of 
vertebrates.  (A-D)  neurones  from  an  ascending  series  of  vertebrates,  (a-e)  the 
stages  in  the  development  of  cells  in  man.  (A )  frog ;  (B)  lizard ;  (C)  rat ;  (D) 
man.  (a)  neuroblast  without  dendrites;  (6)  commencing  dendrites;  (c) 
dendrites  further  developed ;  (d)  first  appearance  of  collaterals ;  (e)  further 
development  of  collaterals  and  dendrites.  (From  Howell:  'Text-book  of 
Physiology,'  Fig.  83,  after  Ramon  y  Cajal.) 

justed  to  its  surroundings.  As  we  go  higher,  nerve-cells 
are  present,  but  they  are  few  and  the  connections  are 
relatively  scant.  Behaviour  is  more  complicated  as  the 
nervous  system  is  better  developed.  In  the  lower  verte- 


THE   NERVOUS    SYSTEM  19 

brates,  a  reptile  for  example,  the  nervous  system  is 
larger,  the  parts  are  more  highly  developed,  and  the 
connections  between  the  elements  are  more  numerous. 
The  movements  are  also  more  numerous,  and  they  are 
more  closely  adapted  to  the  environment.  The  animal 
is  better  equipped  to  live  and  to  act.  The  climax  of 
evolution,  both  in  behaviour  and  in  the  structure  and 
connections  of  the  nervous  system,  is  found  in  man. 
In  short,  mind  or  behaviour  develops  in  the  same  degree 
as  the  nervous  system,  whether  we  measure  the  develop- 
ment of  the  nervous  system  by  the  character  of  the 
nerve  unit,  by  the  nature  of  the  connection  between 
nerve  units,  or,  with  few  exceptions,  by  the  ratio  of 
nervous  tissue  to  body  weight. 

Defects  of  Brain  and  Mental  Defects.  —  The  evidence 
from  pathology  for  the  close  relation  of  mind  and  body  is 
even  more  striking.  A  slight  injury  to  the  head  may 
destroy  consciousness.  Injury  to  certain  small  portions 
of  the  brain  gives  rise  to  paralyses  of  small  groups  of 
muscles,  to  other  portions  causes  the  loss  of  some  sense. 
Injury  to  almost  any  portion  of  the  nervous  system 
impairs  some  capacity  in  some  degree.  Conversely  if 
behaviour  or  consciousness  is  affected,  some  change  in 
the  nervous  system  is  usually  found.  These  two  facts 
taken  in  connection  with  what  we  know  of  physiology, 
and  what  can  be  seen  directly  of  the  action  of  nerve  in 
connection  with  muscle  in  the  lower  organisms,  suffice 
to  make  indisputable  the  very  intimate  relation  between 
mind  and  brain. 

Development  of  the  Nervous  System.  —  It  is  perhaps 
easiest  to  understand  the  nervous  system  if  we  consider 


20  THE   ESSENTIALS   OF   PSYCHOLOGY 

it  in  connection  with  the  development  of  the  animal 
organism  from  the  lowest  forms.  All  higher  organisms 
can  be  regarded  as  developed  from  the  simplest  of  uni- 
cellular forms.  The  amoeba  may  be  regarded  as  the 
type  of  the  original  simplest  animal.  The  amoeba  is  a 
single  cell.  This  cell  is  at  once  nervous  system  and 
muscle,  mouth  and  stomach.  When  it  moves,  the  cell 
contracts  or  expands  or  changes  its  form  as  a  whole. 
When  it  is  stimulated,  the  impression  is  received  by 
part  of  the  cell  and  the  result  is  to  call  out  a  contraction 
in  the  same  and  in  neighbouring  parts.  When  the 
stimulus  is  a  food  particle,  it  induces  a  movement  of 
the  cell  or  part  of  it  toward  the  particle  and  about  it 
until  the  particle  is  entirely  surrounded.  Then  the 
same  protoplasm  that  received  the  stimulus  apparently 
acts  as  a  digestive  organ  to  assimilate  the  morsel.  The 
original  cell  is  thus  possessed  in  some  degree  of  the 
capacities  of  all  parts  of  the  human  or  higher  organism. 
The  development  of  the  higher  organisms  may  be  re- 
garded as  due  -to  the  coming  together  of  many  of  these 
simplest  cells  to  form  a  single  whole  or  colony.  Whether 
or  not  separate  cells  ever  did  combine  in  this  way  is  a 
matter  of  indifference.  It  at  least  illustrates  the  nature 
of  the  relation  of  simple  cells  to  the  more  complicated 
organism.  The  different  cells  take  on  different  func- 
tions and,  in  many  cases,  different  forms.  No  matter 
how  changed,  each  cell  of  the  body  is  regarded  as  a 
separate  organism  that  has  lost  something  of  its  in- 
dividuality, but  is  nevertheless  descended  directly  from 
the  independent  amceba-like  prototype.  The  bone  cells 
perhaps  are  most  removed  from  the  original ;  the  white 


PARTS    OF   THE    NERVOUS    SYSTEM  21 

corpuscles  of  the  blood  have  changed  hardly  at  all. 
Next  to  the  white  blood  corpuscles  the  nerve-cells 
probably  have  been  least  changed  from  the  original 
type.  Except  for  its  dependence  upon  the  other  mem- 
bers of  the  colony  for  its  food,  and  for  the  fact  that  the 
other  cells  serve  to  give  it  form,  a  nerve-cell  is  still 
independent.  The  function  of  the  nerve-cells  in  the 
colony  is  to  make  possible  the  coordination  of  the 
activities  of  the  cells.  When  one  cell  is  stimulated,  a 
group  of  cells  at  a  distance,  constituting  a  muscle,  may 
respond.  The  nerve-cells  compel  the  parts  to  act 'to- 
gether and  make  the  organism  a  unit  for  action  rather 
than  a  mere  mass  of  separate  entities.  , 

The  Divisions  of  the  Nervous  System.  —  As  one  looks 
at  the  central  nervous  system  of  man,  one  can  observe 
three  fairly  distinct  structures,  (i)  The  largest  is  the 
cerebrum,  enclosed  by  the  skull.  This  is  a  mass  roughly 
like  a  sphere  much  corrugated  on  its  surface  by  irregular 
folds.  The  folds  are  known  as  convolutions;  the  de- 
pressions between,  as  fissures.  Two  of  the  fissures  are 
most  prominent.  One,  the  median  fissure,  serves  to 
divide  the  cerebrum  into  two  parts  throughout  more 
than  half  its  height.  It  is  in  the  approximate  centre  of 
the  mass.  This  division  makes  it  customary  to  regard 
the  halves  as  distinct,  and  hence  we  speak  of  the  two 
hemispheres.  The  other,  on  the  outer  side  of  each 
hemisphere,  is  not  so  deep,  and  is  known  as  the  fissure 
of  Sylvius.  Slanting  upward  from  the  lower  front  part 
of  the  brain,  it  will  be  seen  from  the  diagram  to  con- 
stitute a  prominent  landmark.  (2)  Below  the  cerebrum 
at  the  back  are  large  masses  of  nerve-cells  and  connect- 


Cer, 


FIG.  2.  —  Shows  the  nervous  system  as  a  whole.  The  figure  on  the  left  repre- 
sents the  relation  of  the  nervous  system  to  the  body  as  a  whole,  that  on  the 
right  the  nervous  system  exposed  and  seen  from  the  front.  (Cer.)  the  cere- 
brum ;  (Cb.)  the  cerebellum ;  (Sp.  C.)  the  spinal  cord ;  (P)  the  pons ;  (M)  the 
medulla.  The  other  letters  in  the  right-hand  figure  designate  nerve  trunks 
going  to  the  central  nervous  system.  (From  Angell:  'Psychology,'  Fig.  12.) 


PARTS    OF   THE   NERVOUS    SYSTEM  23 

ing  masses  of  white  fibre.  These  together  constitute 
what  is  called  the  brain  stem.  Among  them  are  the 
cerebellum  at  the  back,  the  pons  in  front,  and  the 
medulla  below.  Each  can  be  made  out  in  Figure  2. 
The  other  structures  in  this  region  are  too  numerous 
to  mention,  and  the  action  is  too  complicated  to  dis- 
cuss within  the  limits  of  our  brief  sketch.  (3)  Lowest  is 
the  cord.  The  whole  mass  is  contained  in  a  bony  box. 
The  cerebrum,  the  cerebellum,  and  the  brain  stem  are 
within  the  skull;  the  cord,  within  the  spinal  column. 
From  the  central  nervous  system  nerves  extend  to  the 
sense  organs  and  muscles.  The  sense  organs  in  the  head 
send  their  nerves  to  the  brain  stem.  The  sensory 
nerves  entering  the  cord  have  enlargements  near  the 
cord,  the  spinal  ganglia,  which  contain  cell  bodies.  In 
addition  to  the  central  nervous  system  which  alone  we 
shall  consider,  there  are  masses  of  cells  in  many  parts 
of  the  trunk  and  head  with  relatively  few  connections 
with  the  central  system.  These  are  the  ganglia  of  the 
sympathetic  system. 

White  Matter  and  Grey  Matter.  —  Each  of  these 
large  masses  when  cut  across  shows  some  tissue  of  a 
reddish  grey  colour,  the  grey  matter,  and  other  tissues 
of  glistening  white,  the  white  matter.  Isolated  masses 
of  grey  matter  are  called  ganglia  (singular,  ganglion). 
The  grey  matter  is  made  up  of  cell  bodies,  the  white 
matter  of  nerve  fibres.  In  the  cord  the  grey  matter 
is  in  the  centre,  where  it  constitutes  a  butterfly-shaped 
central  core.  The  butterfly  shape  is  well  marked  in 
the  sections,  as  can  be  seen  in  Figure  7.  In  the  cere- 
brum and  the  cerebellum  the  cell  bodies  are  for  the 


THE   ESSENTIALS   OF   PSYCHOLOGY 


most  part  upon  the  cortex  (bark),  the  outermost  layer; 
the  white  connecting  parts  are  within  and  below.  In 
the  medulla  and  brain  stem,  no  law  for  the  distribution 
of  white  and  grey  matter  can  be  stated  in  a  few  words. 
Strands  of  fibres  are  interspersed  with  masses  of  cell 
bodies,  —  here  one,  there  the  other,  is  on  the  surface. 
The  Growth  of  the  Nervous  System.  —  The  architec- 
ture of  the  different  parts  can  be 
understood  most  clearly  from  a 
study  of  the  development  of  the 
system.  In  the  early  stages  of 
the  embryo  the  central  nervous 
system  is  but  a  groove  in  the 
outer  layer  of  the  mass.  This 
groove  gradually  becomes  deeper, 
and  the  tops  of  the  sides  ap- 
proach until  they  grow  together 
to  form  a  tube.  The  different 
parts  of  the  entire  nervous  sys- 
tem grow  from  different  parts  of 
the  wall  of  the  tube.  The  origi- 
nal hollow  persists  to  the  adult 
stage  and  is  modified  by  the 
changes  in  the  shape  of  the  wall. 
The  brain  develops  from  the  anterior,  the  cord  from  the 
posterior  part  of  the  tube.  The  anterior  portion  of  the 
tube  is  first  constricted  in  two  places  to  form  three  vesi- 
cles ;  later  the  anterior  and  posterior  again  divide  to  make 
five  vesicles  in  all.  See  Figure  3.  The  hemispheres  of 
the  cerebrum  grow  out  at  the  sides  of  the  anterior  or 
head  end  and  grow  up  and  back  until  they  cover  the 


FIG.  3.  —  Development  of  the 
brain  vesicles.  The  hemi- 
spheres are  seen  growing 
from  the  sides  of  the  ante- 
rior end.  The  tube  shows 
the  first  two  constrictions 
and  three  vesicles. 


ELEMENTS    OF   THE   NERVOUS   SYSTEM  2$ 

structures  that  develop  from  the  other  vesicles.  The 
structures  of  the  brain  stem  develop  by  the  thickening 
of  the  walls  of  the  four  lower  vesicles,  or  swellings  of 
the  tube,  and  the  cord  from  the  posterior  part  of  the 
tube.  The  connections  of  the  parts  retain  in  the  adult 
many  traces  of  the  earlier  stages  of  development.  The 
relation  of  the  parts  was  not  well  understood  until  the 
development  of  the  system  was  known. 

The  Elements  of  the  Nervous  System.  —  We  may 
represent  the  nervous  system  most  clearly  as  a  colony 
of  some  eleven  thousand  million  amceba-like  organisms 
crowded  together  for  the  most  part  within  the  bony 
wall  of  the  skull  and  spinal  column  with  prolongations 
extending  to  all  parts  of  the  organism.  The  unit  of 
the  nervous  system  is  the  neurone.  Each  is  connected 
with  numerous  other  units,  and  also  at  innumerable 
points  stands  in  close  functional  relations  to  the  other 
cells  of  the  body.  To  understand  the  action  of  the 
nervous  system  we  must  learn  to  know  (i)  the  character 
of  the  single  unit  and  (2)  the  connections  the  units  make 
with  each  other  and  with  other  parts  of  the  body.  The 
neurone  consists  of  a  cell  body  and  two  sorts  of  pro- 
longations or  processes,  the  axone  or  axis  cylinder,  and 
the  dendrites.  The  axone  is  a  long,  hairlike  extension 
that  may  reach  more  than  half  the  length  of  the  body. 
Most  nerves  are  bundles  of  axones.  The  axone  or- 
dinarily terminates  by  splitting  into  branches,  —  the 
end-brush.  The  dendrites  are  similar  to  the  end-brush. 
They  are  made  up  of  a  number  of  branches  of  the  cell 
protoplasm  and  are  usually  relatively  short.  The  func- 
tion of  the  dendrite  is  to  carry  impulses  to  the  cell 


26 


THE   ESSENTIALS   OF   PSYCHOLOGY 


bodies;  the  function  of  the  axone  is  to  carry  them 
away  from  the  cell  bodies.  The  end-brush  of  one  cell 
is  ordinarily  in  contact  with,  or  very  near,  the  dendrites 
of  other  cells.  The  points  of  contact  are  called  the 
synapses.  The  form  of  the  neurone  varies  greatly.  In 
some  cases  the  cell  body  is  approximately  round  and 


FIG.  4.  —  A  group  of  human  nerve-cells  drawn  to  the  same  scale,  (a)  small 
cell  from  ventral  horn  of  the  cord ;  (6)  cell  from  Clarke's  column,  thoracic 
cord ;  (c)  small  nerve-cell  from  tip  of  dorsal  horn,  thoracic  cord ;  (d)  spinal 
ganglion  cell,  cervical  root ;  (e)  three  granules  from  cerebellum ;  (/)  Purkinje 

I  cell  from  cerebellum ;  (g)  small  pyramidal  cell  from  second  layer  of  central 
gyri  of  cortex ;  (h)  giant  pyramidal  cell  from  the  same  region.  (From  Don- 
aldson, in  the  'Amer.  Text-book  of  Physiology,'  after  Adolf  Meyer.) 

relatively  smooth.  In  other  cases  it  is  more  spindle- 
shaped,  in  others  again  the  surface  is  much  broken  by 
the  processes.  In  certain  parts  of  the  cortex  the  cells 
are  almost  pyramidal  in  their  general  shape,  with  pro- 
cesses at  each  of  the  angles.  In  the  spinal  ganglia  the 
cells  that  receive  and  transmit  the  impressions  from  the 


THE   NEURONE  27 

skin  and  muscles  have  dendrites  and  axones  combined 
in  a  single  process.  The  division  is  only  recognizable 
some  little  distance  from  the  cell  body.  All  of  these 
forms  are  to  be  regarded  as  departures  from  the  type. 
But  the  character  of  the  cell  has  no  demonstrable  rela- 
tion to  the  function.  The  number  of  dendrites  and  the 
number  of  branches  of  the  axone  determine  the  number 
of  connections  that  the  cell  may  make ;  the  form  of  the 
cell  depends  upon  the  number  and  position  of  the 
processes,  but  so  far  as  is  known  that  is  the  only  re- 
lation that  holds  between  form  and  function. 

The  Parts  of  the  Neurone.  —  The  neurone  is  a  vital 
unit.  The  processes  receive  nourishment  only  from  the 
cell  body,  and  when  cut  off  from  the  cell  body,  they  die. 
The  substance  or  protoplasm  of  the  cell  body  is  continu- 


FIG.  5.  —  Longitudinal  and  transverse  sections  of  medullated  nerve  fibre  from  the 
sciatic  nerve  of  frog.  The  myelin  sheath  is  shown  in  black,  the  central  proto- 
plasm shows  its  fibrous  structure.  (From  Barker,  Fig.  80,  after  Biedermann.) 

ous  with  the  protoplasm  of  the  processes.  The  central 
protoplasm  of  the  neurone  shows  no  important  differences 
in  the  character  of  its  parts.  The  only  points  worthy  of 
mention  are :  (i)  the  sheaths  of  the  axone,  and  (2)  the 
nucleus  of  the  cell  body.  Two  sheaths  may  be  distin- 


28  THE   ESSENTIALS    OF   PSYCHOLOGY 

guished,  an  inner  or  myelin  sheath,  and  an  outer,  the 
neurilemma.  The  inner  sheath  is  found  in  all  except  a 
few  fibres  in  the  higher  centres,  the  second  is  present 
outside  of  the  central  nervous  system.  In  the  sympa- 
thetic system  the  outer  sheath  is  usually  the  immediate 
covering  of  the  protoplasm.  The  myelin  sheath  seems 
to  have  some  importance  for  the  function  of  the  neurone, 
but  just  what  has  not  been  made  out.  The  nucleus  of 
the  cell  stands  in  some  vital  relation  to  the  action  of  the 
cell.  In  fatigue  the  nucleus  has  been  shown  to  become 
smaller  and  irregular  in  outline.  Its  exact  function, 
however,  has  not  been  determined.  Recently  small 
fibrils  have  been  traced  within  the  substance  of  the 
nerve-cell,  but  their  function  also  is  not  agreed  upon. 

The  Transmission  of  the  Impulse  within  the  Neurone. 
• — What  goes  on  in  the  neurone  when  it  acts  has  not 
been  definitely  determined.  Theories  have  varied  at 
different  periods  from  assuming  that  some  fluid  was 
transmitted  through  the  nerves  or  that  some  wave  was 
propagated  along  the  substance  of  the  nerve,  to  the 
assumption  that  the  action  was  electrical  in  character. 
To-day  a  generally  accepted  theory  is  that  the  impulse 
is  due  to  some  form  of  chemical  change  which  spreads 
through  the  neurone.  This  hypothesis  is  supported  by 
several  facts,  (i)  The  rate  of  propagation,  about  one 
to  two  hundred  metres  a  second,  is  altogether  too  slow 
for  electrical  transmission,  but  is  within  the  limits  of 
chemical  action.  (2)  The  action  of  the  nerve-cell  is 
accompanied  by  electrical  phenomena.  Whenever  a 
nerve  is  stimulated,  an  electric  current  passes  from  the 
cut  end  of  the  nerve  to  the  uninjured  sheath.  If  a 


THE   NERVOUS   IMPULSE  29 

frog's  nerve  be  dissected  out  and  one  end  be  connected 
to  a  point  on  the  neurilemma  through  a  delicate  galva- 
nometer, the  galvanometer  will  indicate  the  passage  of 
an  electric  current  when  the  nerve  is  stimulated  in  any 
way.  Similar  electric  currents  are  induced,  as  is  well 
known,  by  the  chemical  action  in  a  battery.  (3)  The 
action  of  nerve-cells  frees  certain  chemical  substances, 
products  of  decomposition,  that  are  removed  by  the 
blood.  These  three  facts  point  to  the  assumption  that 
action  of  the  nerves  is  due  to  some  chemical  change. 
This  assumption  fits  in  with  most  of  our  detailed  knowl- 
edge of  the  action  of  the  nervous  system.  Our  picture 
of  the  propagation  of  an  excitation  through  a  neurone 
is  that  it  corresponds  to  the  spread  of  chemical  processes 
through  its  substance  in  very  much  the  same  way  that 
a  spark  runs  along  a  train  of  gunpowder.  In  the  nerve 
the  burning  is  but  partial,  and  the  materials  used  up 
are  constantly  replenished  from  the  blood,  but  both 
processes  are  oxidations,  —  in  each  the  destruction 
spreads  from  part  to  part  within  the  mass. 

An  alternative  theory  that  is  coming  into  favor  re- 
gards the  local  electrical  effects,  excited  by  the  chemical 
changes,  as  more  closely  connected  with  the  nervous 
conduction.  In  the  normal  living  organism  the  change 
is  transmitted  only  in  one  direction.  The  stimulus  is 
always  received  by  the  dendrite  and  is  transmitted 
along  the  axone  to  the  end-brush.  It  never  runs  in 
the  reverse  direction.  One  apparent  exception  may  be 
noted.  The  cells  in  the  spinal  ganglia  receive  the  im- 
pressions from  the  skin  by  a  long  process  that  extends 
to  the  surface  of  the  body  and  is  in  its  structure  similar 


30  THE   ESSENTIALS   OF  PSYCHOLOGY 

to  an  axone.  We  may  either  call  this  a  peculiar  form 
of  dendrite  or  regard  it  as  an  exception  to  the  law  that 
the  axis  cylinder  does  not  receive,  but  always  transmits, 
the  impulse.  Which  of  the  alternatives  for  disposing 
of  the  exception  is  to  be  adopted  is  not  as  yet  a  matter 
of  common  agreement. 

Our  picture  of  the  nervous  system  is  of  a  mass  of  ten 
thousand  millions  or  so  of  these  minute  organisms  en- 
closed within  a  bony  case,  the  skull  and  the  spinal 
column.  Each  cell  is  structurally  independent,  but  the 
terminals  are  in  contact.  In  the  mass  we  ordinarily 
distinguish  three  sorts  of  neurones,  —  the  sensory,  the 
motor,  and  the  associating.  The  difference  is  one  of 
connection  and  function  rather  than  of  structure.  The 
sensory  are  receiving  neurones;  the  motor  send  im- 
pressions out  to  the  muscles,  while  the  associating 
neurones  serve  to  bring  sensory  and  motor  neurones 
into  connection.  As  the  sensory  neurones  always  lead 
towards  the  centre,  they  are  sometimes  called  centripetal 
or  afferent,  and  for  a  similar  reason  the  motor  neurones 
are  the  centrifugal  or  efferent  elements.  There  is  no 
constant  difference  in  structure  between  sensory  and 
motor  neurones.  The  difference  in  function  is  prob- 
ably largely  dependent  upon  the  connections.  In 
terms  of  neurones  the  white  matter  is  made  up  largely 
of  axones,  the  prolongations  of  cell  bodies;  the  grey 
matter  is  a  mass  of  cell  bodies.  Neither  can  be  under- 
stood apart  from  the  other.  The  white  matter  is  merely 
a  bundle  of  transmitting  fibres,  the  grey  matter  nothing 
more  than  a  mass  of  central  cells,  but  every  fibre  of  the 
white  matter  is  a  prolongation  of  some  cell  body  and 
cannot  live  without  it. 


REFLEX   ARCS 


The  Connec- 
tions of  Neu- 
rones. —  The 
action  of  the 
neurone  is  de- 
pendent upon 
its  connections. 
A  cell  never  acts 
alone.  It  is 
always  a  link  in 
a  reflex  arc. 
All  action  of  an- 
imal or  man  is 
excited  by  some 
stimulus  in  the 
external  world, 
and  every  sen- 
sory excitation 
ends  in  some 
movement. 
The  reflex  arc 
in  the  nervous 
system  always 
has  its  origin  in 
a  sense-organ 
and  ends  in  a 
muscle.  In  be- 
tween there 
may  be  any 
number  of  asso- 
ciatory  cells, 


FIG.  6.  —  Shows  the  first  and  third  of  the  three  levels. 
B,  the  short  path  through  the  cord;  A,  the  longest 
path  through  the  cortex.  The  second  level  through 
the  brain  stem  is  not  indicated.  (From  Van 
Gehuchten :  '  Systeme  nerveux  de  I'homme.') 


32  THE   ESSENTIALS   OF   PSYCHOLOGY 

but  these  beginning  and  end  structures  must  always  be 
present.  The  problem  of  action  from  the  side  of  nerve 
physiology  is  one  of  determining  the  paths  of  connection 
between  the  sensory  and  motor  neurones.  The  course 
of  transmission  from  neurone  to  neurone  is  determined 
by  the  openness  of  the  paths.  These  connections  are 
in  part  fully  formed  in  the  organism  at  birth,  in  part 
they  are  acquired  through  the  activities  of  the  animal 
during  life.  Of  these  paths  of  connection  we  may  rec- 
ognise three  levels:  first,  the  direct  connections  of  the 
cord;  second,  the  paths  through  the  brain  stem,  the 
medulla,  and  general  midbrain  region;  and  third,  the 
more  indirect  and  complicated  lines  of  connection  in  the 
cerebral  cortex.  Each  is  to  be  looked  upon  as  a  path 
between  sense-organ  and  muscle.  They  are  different 
ways  by  which  the  sensory  impression  may  be  trans- 
mitted to  the  muscle:  they  are  different  primarily  in 
the  directness  with  which  the  transfer  is  made;  the 
higher  paths  permit  more  connections  and  make  pos- 
sible the  cooperation  of  a  greater  number  of  sensory 
impulses  in  the  control  of  movement. 

The  Action  of  the  Cord. — In  the  cord  impressions  from 
the  skin  and  from  internal  structures  are  carried  across 
to  the  muscles  of  limbs  and  trunk.  Through  it  appro- 
priate responses  are  made  to  stimuli  of  various  sorts 
on  the  skin.  Drawing  back  the  hand  when  burned  is 
primarily  due  to  the  nervous  connections  in  the  cord. 
The  simplest  reflexes  of  the  cord  involve  two  neurones 
only.  The  end  organ  in  the  skin  is  connected  with  the 
dendrite  of  the  T-shaped  cell  in  the  spinal  ganglion,  the 
axone  of  that  cell  extends  into  the  butterfly-like  section 


REFLEXES   IN   THE   CORD 


33 


of  grey  matter  in  the  cord,  and  the  end-brush  comes  in 
contact  with  the  dendrite  of  a  cell  on  the  anterior  side  of 
the  cord.  This  motor  cell  in  its  turn  sends  out  an  axis- 
cylinder  to  a  muscle.  The  chemical  change  induced  by 
the  physical  stimulus  travels  to  the  cell  body,  thence  to 
the  end-brush  or 
synapse,  where  it 
excites  an  impulse 
in  the  efferent  neu- 
rone that  travels 
down  to  the  muscle. 
The  chemical 
change  is  trans- 
ferred at  that  point 
from  nerve  to  mus- 
cle and  excites  the 
chemical  change 
involved  in  the 
muscular  contrac- 
tion. The  diagram 
shows  that  the  spi- 
nal cord  consists  of 
a  mass  of  white 
fibres  which  sur- 
round a  core  of 

grey  matter.  In  the  latter  are  the  cell  bodies  of  the 
motor  nerves,  and  the  associating  or  connecting  neurones. 
The  surrounding  white  matter  is  divided  by  the  exten- 
sions or  horns  of  the  grey  matter  into  four  parts  or 
columns.  Of  these  the  posterior  is  made  up  of  axones 
from  the  cells  in  the  spinal  ganglia,  is  sensory  in  func- 


mJV 


FIG.  7.  — Shows  the  simple  reflex  connection 
through  the  cord.  C2,  T-shaped  cell  in  spinal 
ganglion;  sN,  long  dendrite  or  teledendrion 
to  h,  sense  ending  in  skin.  C1,  motor-cell 
connecting  by  axone  n  with  muscle  M . 


34         THE  ESSENTIALS  OF  PSYCHOLOGY 

tion,  while  the  others  are  both  sensory  and  motor,  out- 
growths of  cell  bodies  in  the  central  grey  or  from  cell 
bodies  in  the  cortex  or  brain  stem. 

The  Paths  in  the  Cord.  —  If  the  central  grey  may  be 
regarded  as  the  transferring  station,  the  surrounding 
white  constitutes  the  transmitting  paths  by  which  the 
cortex  and  higher  centres  in  general  are  connected  with 
the  world  outside.  The  sensory  tracts  bring  impres- 
sions in  from  the  periphery  and  transmit  them  to  the 
cerebrum.  The  motor  tracts  serve,  on  the  other  hand, 
to  connect  the  upper  centres  with  motor  cells  in  the 
cord,  and  thus  with  the  muscles  of  the  lower  parts  of 
the  body.  Not  only  do  these  outer  fibre  layers  connect 
the  upper  portion  of  the  nervous  system  with  sense- 
organ  and  muscle,  but  they  also  connect  the  different 
levels  of  the  cord  with  each  other.  A  sensory  impulse 
excites  not  only  muscles  that  have  their  cells  at  the 
same  level  in  the  cord,  but  also  groups  of  muscles  at 
different  levels  above  and  below.  If  we  return  to  con- 
sider the  simple  reflexes,  we  find  that  the  sensory  stimu- 
lus may  spread  not  merely  to  the  single  motor  neurone 
or  group  of  motor  neurones  at  the  same  level,  but  it 
may  make  connections  with  neurones  that  lie  higher 
and  lower  in  the  cord,  or  more  frequently,  it  extends  to 
neurones  lying  in  the  opposite  side  of  the  cord  and  pro- 
duces movements  of  members  on  the  other  side  of  the 
body.  If  one  destroy  the  brain  of  a  frog  or,  by  pith- 
ing, cut  the  cord  off  from  the  upper  nervous  system,  it  will 
be  seen  that  all  of  these  reflexes  may  still  be  called  out  by 
stimuli.  If  a  bit  of  paper  moistened  with  acid  be  placed 
upon  the  left  foot  of  a  frog,  the  foot  will  be  drawn  up.  If 


CONTROL    OF    REFLEXES 


35 


now  the  foot  be  held  so  that  it  cannot  be  moved,  it  will  be 
found  that  the  other  is  brought  over  to  remove  the  stimu- 
lus. If  this  is  not  successful,  the  muscles  of  the  forelegs 
and  trunk  will  contract  and  the  contractions  will  continue 
until  the  stimulus  is  removed  or  the  neurones  exhausted. 
The  first  movement  (of  the  left  leg)  is  due  to  the  transfer 
of  the  stimulus  to  the  motor  cell,  or  cells,  on  the  same 
side  of  the  cord.  When  the  foot  is  held  and  the  stimulus 
grows  strong  enough,  the  impulse  is  transmitted  to  the 
group  of  neurones  on  the  opposite  side  of  the  cord, 
and  muscles  of  the  right  leg  are  contracted.  When  the 
excitation  becomes  still  stronger,  the  discharge  spreads 
to  neurones  higher  up,  and  the  muscles  of  the  trunk  and 
forelegs  are  made  to  contract. 


FIG.  8.  —  Shows  a  synapse  from  the  optic  lobe  of  a  chick.     (From  '  Amer.  Text- 
book of  Physiology,'  Fig.  76,  after  Van  Gehuchten.) 

Action  of  the  Synapse.  —  Since  there  are  evidently 
many  possible  lines  of  transmission,  the  question  natu- 
rally arises,  what  decides  which  of  the  many  paths  shall  be 
followed?  The  answer  is  found  in  a  recent  theory  that 
the  course  of  the  impulse  is  determined  at  the  point  of 
connection  between  neurone  and  neurone,  the  synapse. 
The  end-brush  of  the  receiving  neurone  is  in  contact 
with  the  dendrites  of  several  motor  neurones.  Each  of 


36        THE  ESSENTIALS  OF  PSYCHOLOGY 

these  points  of  contact  or  synapses  has  a  different  resist- 
ance. The  path  to  muscles  of  the  same  leg  is  most 
permeable ;  next  in  degree  of  permeability  are  the 
synapses  to  dendrites  of  the  motor  neurones  that  control 
the  muscles  of  the  other  leg,  while  the  synapses  that 
connect  with  the  muscles  of  the  upper  trunk  open  with 
still  greater  difficulty.  The  lines  of  discharge  depend 
primarily  upon  the  openness  of  the  synapses.  In  these 
lowest  reflexes  the  ease  of  transmission  depends  upon 
the  character  of  the  synapses  as  they  are  determined  in 
the  individual  at  birth,  and  thus  the  responses  are  pre- 
pared in  advance  of  any  experience.  When  the  sensory 
excitation  is  weak,  only  the  easiest  paths  are  followed. 
As  the  impulse  becomes  stronger,  more  and  more  diffi- 
cult synapses  will  be  crossed,  and  the  motor  discharge 
will  become  more  and  more  diffuse. 

Reflexes  of  the  Second  Level.  —  At  the  second  level 
of  reflexes  the  same  general  laws  hold.  The  possibilities 
of  connection  are,  however,  very  much  more  numerous. 
Many  senses  contribute  impressions  and  the  muscles  over 
which  the  discharge  may  take  place  now  include  all  of  the 
muscles  of  the  body  instead  of  the  muscles  of  trunk 
and  limbs  only.  The  synapses  for  the  reflexes  of  this 
level  lie  in  the  region  of  the  central  nervous  system  be- 
tween the  top  of  the  cord  and  the  cortex.  The  anatomy 
of  this  region  is  too  complicated  to  be  described  within 
our  limits,  but  the  connections  are  made  in  the  numerous 
accumulations  of  cell  bodies  found  in  the  structures  of 
the  medulla,  midbrain,  and  on  up  to  the  lower  ganglia 
of  the  cerebrum.  Wherever  the  synapses  may  be  located, 
we  may  distinguish  two  general  groups  of  connections. 


FUNCTIONS    OF    THE    BRAIN    STEM  37 

First  each  stimulus  tends  to  excite  certain  movements 
immediately  and  directly.  Thus  in  the  eye,  when  a 
ray  of  light  falls  upon  the  retina,  the  pupil  at  once  con- 
tracts. This  movement  is  called  out  by  the  sensory 
stimulus  transmitted  to  one  of  the  lower  centres  for 
vision.  There  the  motor  neurone  connected  with  the 
muscles  is  excited  and  the  pupil  contracts.  The  visual 
impressions,  too,  excite  and  control  the  movements  of 
the  trunk  and  limbs  through  the  midbrain  centres  and 
their  connections  with  the  motor  tracts  in  the  cord. 
A  frog,  for  example,  that  has  had  its  hemispheres  re- 
moved will  avoid  obstacles  in  swimming  or  hopping 
and  will  give  other  evidences  that  its  movements  are 
guided  by  sight.  In  man  the  neurones  of  the  brain  stem 
are  not  so  independent  of  the  cortex,  and  it  is  difficult  to 
demonstrate  that  they  can  act  alone.  The  functions  of 
these  structures  at  the  second  level  are :  (i)  to  serve  as 
reflex  centres  by  which  the  senses  at  this  level  may  be 
connected  with  muscles  of  the  head ;  (2)  to  connect  the 
special  sense-organs  of  the  head  with  the  motor  neurones 
of  the  cord,  and  so  with  the  muscles  of  trunk  and  limbs ; 
and  (3)  to  connect  the  cortex  with  the  sense-organs  and 
with  the  muscles.  It  is  probable  that  all  the  sense- 
organs  are  represented  in  the  brain  stem  by  neurones,  and 
that  in  every  case  the  impulse  from  a  sense-organ  is 
transferred  from  one  neurone  to  another  in  some  ganglion 
in  this  region.  The  mechanism  of  the  reflexes  is  the 
same  as  in  the  cord.  The  only  difference  is  that  the 
sources  of  excitation  are  more  numerous  and  the  pos- 
sibilities of  connection  are  greater. 
Action  of  Cortex.  —  By  far  the  most  important  divi- 


35  THE   ESSENTIALS   OF   PSYCHOLOGY 

sion  of  the  nervous  system  is  the  cerebrum.  In  man  the 
cerebrum  is  the  largest  of  the  nervous  structures,  con- 
stituting rather  more  than  half  of  the  total  nervous  sys- 
tem. It  is  also  the  part  of  the  nervous  system  most 


FIG.  9.  —  Localization  of  cerebral  function.  The  figure  opposite  shows  the  outer 
surface  of  the  right  hemisphere ;  the  one  above,  the  mesial  surface  of  the  left 
hemisphere.  In  both  figures  the  motor  areas  are  marked  by  horizontal  shading, 
the  sensory  by  vertical  shading,  while  the  associatory  areas  are  unshaded.  The 
doubtful  or  partially  sensory  or  motor  regions  are  indicated  by  dots.  (S)  is 
opposite  the  fissure  of  Sylvius;  (R)  above  the  fissure  of  Rolando.  (M)  is 
above  the  motor  region ;  (C)  above  the  cutaneous  and  kinaesthetic  area.  ( V) 
indicates  the  visual  region;  (0)  is  below  the  olfactory  area.  The  auditory 

closely  related  to  consciousness.  In  fact,  it  is  very 
doubtful  if  any  consciousness  at  all  accompanies  the 
action  of  any  other  portion  of  the  nervous  system.  Its 
structure  and  functions  are  very  complex,  but  our  guid- 
ing principles  still  suffice  to  explain  its  action.  It, 


FUNCTIONS    OF   THE    CEREBRUM 


39 


too,  is  made  up  of  neurones  in  various  connections,  and 
the  neurones  act  to  transfer  sensory  impressions  to 
motor  neurones,  and  so  to  excite  muscles.  The  only 


FA 


TA 


region  is  just  below  the  fissure  of  Sylvius,  above  (H).  (FA)  designates  the 
frontal,  (PA)  parietal,  and  (TA)  the  temporal  association  centres.  There 
is  some  evidence  that  the  dotted  regions  about  the  sensory  and  motor  areas  are 
areas  in  which  particular  associations  are  formed  with  them.  The  diagram 
embodies  the  results  of  A.  W.  Campbell,  but  has  been  modified  in  one  or  two 
respects  to  agree  with  the  results  of  Flechsig  and  Gushing. 

differences  between  it  and  the  structures  considered 
above  are :  (i)  that  it  offers  vastly  greater  possibilities 
of  connection,  and  (2)  that  impressions  received  at  an 
earlier  period  in  the  life  of  the  individual  play  a  large 
part  in  controlling  the  course  of  the  movements.  In 


40  THE   ESSENTIALS   OF   PSYCHOLOGY 

consequence  the  processes  that  intervene  between  stimu- 
lus and  response  may  be  regarded  as  much  more  impor- 
tant here  than  they  are  in  any  of  the  reflexes  already 
considered. 

Localization  of  Cortical  Functions.  —  Cell  bodies 
are  found  for  the  most  part  only  in  the  cortex  or  bark, 
a  superficial  layer  of  the  cerebrum  only  a  few  millimetres 
thick.  The  inner  mass  consists  of  fibres,  axones  of 
cell  bodies  in  the  cortex  or  in  the  brain  stem,  which  serve 
to  connect  different  parts  of  the  cortex,  and  the  cortex 
with  the  muscles  and  sense-organs.  We  must  distin- 
guish three  sorts  of  areas  or  regions  in  the  cortex.  Cer- 
tain areas  receive  the  impressions  from  the  outside  world 
and  are  known  as  the  sensory  regions.  Others  send  out 
impulses  to  the  muscles  and  are  known  in  consequence 
as  the  motor  regions.  The  remaining  areas  serve  to 
connect  the  sensory  and  motor  and  constitute  what 
are  known  as  the  association  areas.  The  first  two  are 
often  grouped  together  as  the  projection  areas,  since 
they  represent  regions  of  the  body  in  very  much  the  same 
way  that  parts  of  the  screen  may  be  said  to  represent  the 
slide  when  a  picture  is  thrown  upon  it  by  the  projection 
lantern.  The  relation  between  these  areas  and  the  sense- 
organ  and  muscle  is  very  close. 

Localization  of  Motor  Areas.  —  The  position  of  the 
motor  region  is  more  easily  demonstrated.  If  the 
brain  of  a  man  be  exposed  for  an  operation  and  the 
motor  area  be  stimulated  electrically,  some  muscle 
of  the  body  will  respond  and  the  same  muscle  or  group 
of  muscles  will  always  respond  provided  the  same 
region  be  stimulated  in  the  same  degree.  The  areas  that 


CEREBRAL    LOCALIZATION  4! 

correspond  to  the  different  muscles  are  sufficiently  well 
known  to  permit  the  physician  to  decide  what  part 
of  the  brain  is  defective  in  case  some  group  of  muscles 
be  paralysed.  The  motor  area  of  the  brain  is  shown 
in  the  diagram.  It  lies  just  in  front  of  the  central 
fissure,  the  fissure  of  Rolando,  and  extends  upward 
from  near  the  fissure  of  Sylvius  to  the  median  fissure 
and  over  to  the  mesial  surface  of  the  hemisphere,  the 
wall  of  the  median  fissure.  As  is  generally  the  case  in 
the  upper  part  of  the  nervous  system,  the  right  brain 
contains  the  motor  centres  for  the  left  half  of  the  body 
and  vice  versa. 

Sensory  Areas.  —  The  sensory  regions  are  scattered 
and  their  positions  are  less  certain  than  the  motor  regions. 
The  part  of  the  cortex  connected  with  the  eye  is  in  the 
back  of  the  brain,  the  occipital  region.  The  area  to 
which  vision  may  certainly  be  ascribed  is  in  the  cuneus,  a 
wedge-shaped  convolution  on  the  mesial  surface.  It  is 
marked  in  the  diagram.  The  auditory  region  is  in  the 
temporal  lobe,  just  below  the  fissure  of  Sylvius  near  its 
junction  with  the  central  fissure.  The  impulses  from 
skin  and  muscle  are  received  in  the  region  just  behind 
the  central  fissure.  Smell  is  less  certainly  localized, 
but  is  probably  on  the  mesial  surface,  as  indicated  in 
the  diagram.  Taste  may  be  near  it,  but  the  localization 
is  hardly  more  than  conjecture  at  the  present  stage  of 
knowledge. 

Association  Areas.  —  It  will  be  noticed  that  after  all 
the  regions  with  known  relations  to  sensation  and  move- 
ment are  enumerated,  the  greater  part  of  the  cortex  is 
left  without  assigned  function.  It  is  the  contention  of 


42  THE   ESSENTIALS   OF   PSYCHOLOGY 

Flechsig,  now  generally  accepted,  that  the  remaining 
portions  of  the  brain  have  as  their  function  to  make  cross 
connections  between  the  sensory  and  the  motor  regions, 
to  unite  sensory  with  motor,  and  sensory  with  sensory 
areas.  For  example,  the  axone  from  a  cell  body  hi  the 
optic  region  extends  to  the  intervening  association 
region  and  there  comes  into  contact  with  the  dendrites  of 
numerous  association  neurones,  each  of  which  in  its  turn 
will  connect  with  other  sensory  or  motor  neurones,  or 
with  other  association  neurones.  Each  intervening  asso- 
ciation neurone  will  increase  the  connections  that  a  sen- 
sory neurone  may  make,  and  so  increase  the  possible 
responses  that  the  same  stimulus  may  call  out. 

Action  of  the  Cortex  during  Speech.  —  If  we  turn  from 
structure  to  function,  we  find  that  the  nervous  excitation 
transmitted  from  the  sense-organ  to  the  sensory  cells 
in  the  cortex  must  sooner  or  later  find  its  way  to  a 
motor  neurone.  In  some  cases  the  motor  cell  affected 
is  in  the  same  region  of  the  brain.  Thus  movements 
of  the  eye  may  be  excited  by  stimulating  the  occipital 
lobes,  and  it  is  probable  that  movements  of  the  eyes 
evoked  by  visual  stimuli  may  have  a  path  in  the  cortex 
that  does  not  extend  beyond  the  wider  limits  of  the 
optic  region.  More  characteristic,  however,  are  the 
interconnections  that  control  the  movements  involved  in 
speech.  These  are  of  interest  because  the  disturbances  of 
speech  were  among  the  earliest  to  receive  an  explanation. 
In  ordinary  repetition  of  spoken  words,  the  excitation  is 
transmitted  from  the  ear  by  way  of  a  lower  centre  to  the 
auditory  region,  thence  along  the  axones  of  sensory  neu- 
rones to  association  neurones  in  the  Island  of  Reil  (the 


THE   CORTEX   IN    SPEECH  43 

bottom  and  sides  of  the  fissure  of  Sylvius)  and  from  there 
to  the  motor  area  for  speech  in  the  lower  Rolandic  region. 
Here  the  end-brushes  of  the  association  neurones  come 
into  functional  union  with  the  dendrites  of  motor  neu- 
rones. The  axones  of  the  motor  neurones  end  through 
the  mediation  of  other  neurones  in  the  muscles  of  the 
vocal  organs  and  the  sound  is  repeated.  That  this  is 
the  approximate  course  of  the  nervous  impulse  we  know 
from  a  comparison  of  the  defects  of  speech  with  the 
injuries  in  different  parts  of  the  brain.  If  the  auditory 
cells  are  destroyed  in  any  way,  the  patient  cannot  repeat 
the  words.  The  effect  is  the  same  as  if  the  ear  were 
destroyed.  Again,  if  there  is  an  injury  to  the  associa- 
tion region  in  the  Island  of  Reil,  the  ability  to  repeat 
words  heard  is  impaired.  Finally,  if  the  motor  centre 
for  speech  is  injured,  speaking  of  any  kind  will  be  im- 
possible. The  condition  is  known  as  aphasia,  —  sen- 
sory aphasia  is  due  to  disturbance  of  the  auditory  region, 
motor  aphasia  to  disturbance  of  the  motor  region.  The 
existence  of  sensory  aphasia  is  of  particular  importance 
as  an  evidence  that  the  action  of  the  cortex  is  dependent, 
like  the  action  of  the  lower  centres,  upon  the  excitations 
of  sense,  that  all  action  is  sensori-motor.  There  is  no 
response  unless  an  impulse  is  received  from  some  sensory 
region. 

The  relations  of  vision  to  speech,  and  of  vision  and 
audition  to  writing,  follow  the  same  general  rules.  When 
one  reads  aloud,  the  impulse  is  transferred  from  the  visual 
area  to  the  motor  speech  region  through  an  association 
centre.  Injury  to  the  visual  area  or  to  the  sight-speech 
association  region  may  interfere  with  the  process.  The 


44  THE   ESSENTIALS   OF   PSYCHOLOGY 

resulting  disease  is  known  as  alexia.  Writing  on  dic- 
tation ordinarily  disappears  with  speech  in  the  sensory 
forms  of  aphasia.  Each  of  these  paths  has  been  devel- 
oped through  long  practice  and  is  relatively  firmly  es- 
tablished. Any  other  simple  response  to  stimulation 
would  take  a  corresponding  course  and  would  involve 
sensory,  associatory,  and  motor  regions.  When  the 
paths  are  less  well  established  and  the  response  is  less 
completely  prepared,  as  when  one  answers  a  question 
and  several  replies  are  possible,  the  association  regions 
probably  play  a  larger  part.  There  are  more  possible 
connections  and  more  open  association  paths,  or  at  least 
the  open  paths  in  the  association  regions  are  more  nearly 
on  a  par.  In  consequence  there  is  smaller  chance  of 
prophesying  in  advance  what  course  the  response  will 
take.  The  necessity  for  the  cooperation  of  sensory, 
associatory,  and  motor  neurones  is  none  the  less  cer- 
tain. 

In  addition  to  the  connections  between  sensory  and 
motor  regions  there  are  a  number  of  cases  in  which 
two  sensory  regions  must  be  connected.  Thus  when 
one  touches  a  pencil  in  the  dark,  the  picture  of  the 
object  will  present  itself  before  the  movement  is  made, 
or  simultaneously  with  the  movement.  In  this  case  the 
tactual  neurones  excite  a  visual  neurone  or  group  of 
neurones.  In  the  perception  processes  such  associatory 
transfers  are  the  rule  rather  than  the  exception,  as  will 
be  seen  in  a  later  chapter.  Ordinarily  the  association 
leads  finally  to  action  of  some  sort,  but  so  far  as  impor- 
tant action  is  concerned,  that  may  be  very  long  delayed. 
This  fact  of  arousing  other  sensory  processes  raises  the 


CORTICAL   ACTION   IN   MEMORY  45 

question  as  to  the  cortical  seat  of  memory  processes  and 
imaginings.  The  most  generally  accepted  answer  at 
present  is  that  the  memories  have  the  same  cortical 
regions,  in  fact  the  same  cortical  cells,  as  the  sensations, 
and  that  in  remembering  the  same  cells  are  excited  as 
in  seeing  or  hearing.  Visual  memories  are  in  the  visual 
region,  auditory  memories  are  in  the  auditory  region, 
and  so  on.  The  process  of  arousing  memories  is  one  of 
retracing  old  paths,  very  much  as  habit  depends  upon 
the  renewed  action  of  a  group  of  motor  neurones.  The 
details  of  the  process  must  occupy  us  in  the  later  chap- 
ters. 

Nerve  Elements  do  not  Act  in  Isolation.  —  One  word 
needs  to  be  added  in  this  connection,  and  that  is  that  the 
single  parts  of  the  nervous  system  probably  do  not  act 
alone.  When  we  speak  of  the  action  of  a  single  group  of 
cells  it  is  probable  that  the  group  is  merely  the  centre 
of  excitation  in  a  very  wide  region.  The  excitation 
that  arouses  that  group  spreads  to  very  remote  parts 
of  the  brain.  Action  is  always  of  large  masses  of  nerve- 
cells,  but  of  the  mass  certain  parts  are  emphasised, 
the  others  respond  in  very  much  slighter  degree.  There 
is  a  complicated  interplay  of  part  and  part  throughout 
a  very  large  portion  of  the  mass  of  neurones,  although 
only  relatively  few  are  in  great  activity.  The  interac- 
tions which  themselves  do  not  directly  affect  action  serve 
to  guide  the  course  of  the  other  responses.  Each  con- 
tributes its  share  to  the  total  action,  although  one  alone 
stands  out  prominently. 

The  action  of  the  nervous  system,  then,  is  always  de- 
pendent upon  a  transfer  of  some  sort  of  energy  from 


46  THE   ESSENTIALS    OF   PSYCHOLOGY 

neurone  to  neurone.  The  original  excitation  is  received 
from  the  external  world  and  has  its  final  outcome  in  some 
sort  of  movement.  At  least  two  sets  of  neurones  are 
involved  in  every  action.  As  the  act  becomes  more 
complicated,  a  larger  and  larger  number  of  neurones 
intervene,  and  a  larger  and  larger  number  of  stimuli 
contribute  to  the  excitation  and  control  of  the  movement. 
At  the  lowest  level  the  stimulus  is  ordinarily  single  or  at 
least  of  one  sort,  and  the  paths  of  motor  discharge  are 
relatively  few.  At  the  second  level  the  neurones  in- 
volved are  still  relatively  few,  but  the  stimuli  are  nu- 
merous and  varied  and  the  paths  of  discharge  are  more 
numerous.  On  the  highest  level  in  the  cortex  very  many 
of  the  sensory  and  motor  paths  are  concerned,  and  in 
addition  the  effects  of  the  stimuli  that  were  earlier  re- 
ceived and  are  stored  in  the  nervous  system  contribute 
their  share  to  the  control  of  action. 

Interaction  between  Cord  and  Cortex.  —  The  different 
levels  ordinarily  interact  in  any  response.  Thus, 
when  the  hand  is  burned  or  pricked  it  will  usually  be 
drawn  back  reflexly.  This  means  that  the  sensory 
impulse  is  transmitted  to  a  spinal  ganglion  and  thence 
to  the  anterior  grey  cells  of  the  cord,  and  so  down  to 
the  muscle.  But  suppose  that  the  man  is  working  in  a 
bit  of  machinery  with  the  hand  in  front  of  a  knife,  and  the 
finger  is  burned.  The  reflex,  if  it  is  not  too  strong  or 
if  the  stimulus  is  not  unexpected,  will  be  checked  by  the 
knowledge  of  the  danger  from  the  knife.  This  means 
that  the  visual  impression  of  the  knife  has  been  carried 
to  the  visual  area  in  the  cortex  by  way  of  the  eye  and 
midbrain  centres.  The  effect  of  the  arousal  of  the  visual 


INTERACTION    IN   THE   NERVOUS   SYSTEM  47 

area  is  transferred  to  the  motor  region,  and  serves  to 
inhibit  the  activity  of  the  motor  cells  in  the  cord  that 
would  otherwise  be  involved  in  the  reflex,  or  it  may  con- 
tract the  muscles  that  oppose  the  reflex.  In  this  way 
the  impressions  from  the  eye  or  the  memories  derived 
from  the  eye  oppose  and  may  overcome  the  effects  of 
the  excitation  from  the  skin.  The  movement  is  con- 
trolled, not  by  the  tactual  sensations  alone,  but  by 
tactual  sensations  together  with  any  visual  sensations 
and  memories  that  bear  upon  the  situation.  At  each 
level  in  the  nervous  system  as  we  go  upward  from  the 
cord,  there  are  more  neurones  involved.  The  action 
is  in  the  light  of  a  constantly  increasing  number  of 
sensations,  and  many  more  forms  of  response  are  possible. 
But  the  difference  is  one  of  complexity  alone.  The 
beginning  and  the  end  of  the  process  may  be  identical. 
The  impulse  is  propagated  in  the  same  way  and  the 
laws  that  govern  the  selection  of  the  path  are  the  same. 
Our  first  picture  of  the  simple  reflex  explains  the  funda- 
mentals of  the  most  complicated  voluntary  act.  It  is 
only  necessary  to  add  new  stimuli  and  new  possibilities 
of  response,  —  to  recognise  that  many  currents  of  nervous 
activity  are  adding  their  quota  to  the  control  of  action. 

QUESTIONS 

1.  What    is    the    sheath    of    the    axone?     (a)   neurilemma  ? 
(b)  medullary  sheath  ? 

2.  Distinguish  afferent  nerves,  efferent  nerves,  ganglia,  white 
and  grey  matter  in  terms  of  the  parts  of  neurones  or  relations  of 
neurones  that  compose  them. 

3.  Describe  the  functions  of  the  nervous  system  in  the  simplest 
and  most  general  terms. 


40  THE   ESSENTIALS   OF   PSYCHOLOGY 

4.  What  passes  along  the  nerve  as  an  impulse  is  transmitted? 
How  is  the  action  of  the  neurone  like  that  of  an  amoeba  ?  like  that 
of  a  battery? 

5.  How  are  the  acts  controlled  by  the  three  levels  of  the  nervous 
system  similar?  how  different ? 

6.  What  level  is  involved  in  each  of  the  following  acts? 

Drawing  up  the  foot  when  the  sole  is  tickled. 

Sneezing  as  you  breathe  in  dust. 

Winking  as  the  eye  is  threatened. 

Turning  a  corner  when  thinking  of  something  else. 

7.  What  difference  is  there  between  the  function  of  the  anterior 
and  posterior  association  centres? 

8.  Why  does  injury  to  the  left  side  of  the  cerebrum  produce  a 
paralysis  on  the  right  side  of  the  body? 

EXERCISES 

1.  Draw  neurones  of  three  different  types.    Designate  axones, 
dendrites,  and  end-brush  of  each.    How  many  axones  has  a 
neurone?  how  many  dendrites ?  how  many  end-brushes ? 

2.  Draw  a  diagram  to  illustrate  the  course   followed  by  an 
impulse  when  you  burn  your  finger. 

3.  Draw  a  cross  section  of  the  cord.     Show  the  path  followed 
by  a  simple  reflex. 

4.  Draw  the  cerebrum  in  lateral  and  mesial  view  and  indicate 
the  sensory,  motor,  and  associatory  areas. 

5.  Trace  on  the  diagram  the  path  followed  by  an  impulse  as  you 
copy  a  sentence  from  a  book. 

6.  If  possible  examine  neurones  and   their  connections  in  a 
section  of  a  cord  under  a  microscope. 

7.  If  opportunity  offers  procure  the  brain  of  an  animal,  sheep 
or  cat,  dissect  it,  and  compare  the  structures  with  the  diagrams. 

REFERENCES 

Ho  WELL  :  Physiology,  Section  II. 
McDoucALL :  Primer  of  Physiological  Psychology. 
QUAIN  :  Anatomy,  vol.  iii. 
HERKICK  :  Introduction  to  Neurology. 


CHAPTER  in 

NEURAL  ACTION  IN  RELATION  TO  CONSCIOUSNESS 
AND  BEHAVIOUR 

AFTER  a  discussion  of  the  structure  and  action  of  the 
nervous  system  the  question  of  the  relation  between  these 
physical  processes  and  the  mental  processes  or  behaviour 
naturally  arises.  Popularly  there  is  a  tendency  to  con- 
fuse mind  with  brain.  A  man  is  said  to  have  a  good 
brain  when  it  is  meant  merely  that  he  is  effective  or 
unusually  intelligent.  This  identification  is  altogether 
without  warrant.  On  the  contrary,  there  is  little  if 
any  similarity  between  nejvous  activity  and  the  mental 
state.  If  one  could  bring  the  processes  that  go  on  in 
the  brain  when  one  looked  at  a  landscape  side  by  side 
with  the  landscape  itself  and  compare  them,  the  two 
would  not  be  at  all  alike.  Where  the  landscape  shows 
various  forms  and  masses  of  colour,  the  nervous  activity 
would  show  chemical  reactions  running  here  and  there 
in  the  visual  area  at  the  back  of  the  brain  and  in  the 
nerves  leading  to  and  away  from  it.  We  have  every 
reason  to  believe  that  the  chemical  changes  stand  in 
some  essential  relation  to  the  mental  processes,  but 
it  is  obviously  impossible  to  assert  that  the  two  are 
identical  or  even  that  they  are  similar  in  character. 
One  of  the  problems  most  discussed  in  psychology  and 
in  philosophy  is  what  is  the  exact  relation  between  these 

E  49 


50        THE  ESSENTIALS  OF  PSYCHOLOGY 

constantly  shifting  chemical  changes  in  the  nervous 
system  as  the  landscape  affects  it  and  the  mental  image 
of  the  landscape ;  or,  in  general,  between  brain  action 
and  consciousness.  While  the  answer  makes  little  prac- 
tical difference  for  the  treatment  of  psychological  prob- 
lems, it  is  well  before  going  farther  to  have  a  statement 
of  opposing  theories  and  a  provisional  working  hy- 
pothesis. 

Relation  of  Mind  and  Body.  —  A  large  part  of  the 
difficulty  in  understanding  the  relation  of  body  and  mind 
grows  out  of  the  different  ways  in  which  one  must  ap- 
proach the  explanation  of  behaviour.  The  observer  sees 
only  the  stimulus  or  occasion  for  the  action,  the  actor 
appreciates  the  mental  states  that  follow  the  stimulus 
and  precede  the  action,  but  neither  can  see  both  sides  at 
once.  Even  if  the  observer  calls  anatomy  and  physiology 
to  his  aid  and  goes  as  far  as  he  can  by  analogy  from  ex- 
periments on  animals  in  the  attempt  to  find  an  explana- 
tion of  behaviour,  he  gets  only  nerves  and  then-  connec- 
tions ;  he  can  never  have  a  view  of  the  consciousness  of 
the  actor.  The  actor  from  his  side  can  never  pass  beyond 
consciousness;  he  does  not  become  aware  directly  of 
nerve  or  nervous  activity,  no  matter  how  he  may  seek 
to  penetrate  beneath  his  immediate  consciousness.  The 
outside  observer  sees  excitations  vanish  into  the  nervous 
system  and  sees  actions  result ;  the  actor  sees  the  occa- 
sion for  his  act  approach,  is  conscious  of  the  resulting 
sensation,  and  knows  that  he  has  acted,  but  knows  noth- 
ing of  the  nervous  system  that  intervenes.  So  far  no 
one  has  been  able  to  bring  the  two  aspects  of  behaviour 
together  in  a  single  system  of  explanations,  either  by 


BODY   AND   MIND  51 

direct  observation  or  in  theory.  At  present  it  is  uni- 
versally accepted  that  mental  state  and  bodily  or  nervous 
activity  are  always  found  together,  but  care  is  taken 
not  to  assert  that  one  is  the  cause  of  the  other.  The 
implication  is  that  they  are  related  in  some  essential 
and  fundamental  way,  but  what  that  relation  is,  is  not 
stated.  It  is  customary  to  explain  any  mental  process 
in  terms  of  other  mental  processes,  and  to  explain  all 
nervous  action  by  other  nervous  activities,  but  no 
attempt  is  made  to  explain  one  in  terms  of  the  other, 
further  than  to  say  that  the  two  series  are  always  found 
together  and  run  on  side  by  side.  For  our  purposes 
it  is  not  necessary  to  discuss  the  theories  that  have 
been  developed  to  explain  the  connection.  We  may 
leave  the  whole  problem  open,  as  the  facts  of  psychology 
are  the  same  whatever  theory  may  ultimately  prevail. 
For  convenience  we  shall  often  seem  to  imply  that 
activity  in  sensory  neurones  produces  changes  in  con- 
sciousness and  that  ideas  start  the  motor  discharges 
which  lead  to  action.  This  is  not  to  be  regarded  as 
committing  the  author  to  any  theory  of  the  real  connec- 
tion between  body  and  mind,  but  as  a  lapse  into  popular 
speech. 

The  Connections  of  Neurones.  —  While  it  is  assured 
that  consciousness  is  dependent  upon  the  activity  of 
the  nervous  system,  and  that  certain  conscious  processes 
are  connected  with  the  activity  of  certain  nervous 
structures,  it  is  also  important  to  know  what  change  there 
is  in  the  elements  of  the  nervous  system  as  a  result  of 
action.  Upon  their  changed  character  as  a  result  of 
earlier  action  depends  most  of  the  possibility  of  educa- 


THE    ESSENTIALS    OF   PSYCHOLOGY 


tion   and    of   improvement    in    behaviour.     Formation 
of  habits  and  the  acquirement  of  memories  are  the  most 

striking  of  the 
mental  and 
physical  capaci- 
ties directly  re- 
ferred to  the 
nervous  system. 

i  \  i  At   present    the 

~~}  »  tendency    is    to 

explain  all  learn- 
ing as  due  to  a 
change  at  the 
point  where  two 
neurones  come 
together,  where 
the  end-brush  of 
one  comes  into 
contact  with  the 
dendrites  of  an- 
othei.  This 
point,  as  was 
said,  has  been 
called  the  syn- 
apse. As  was 
seen  in  the  pre- 
ceding chapter, 
the  synapse  gov- 
erns the  course  of  the  impulse.  Each  sensory  path 
makes  connections  with  several  motor  and  associating 
paths  or  neurones  and  any  impulse  will  take  the  path 


FIG.  10.  —  Shows  the  complexity  of  interconnections 
(number  of  synapses)  between  neurones  in  the 
cortex.  (From  Barker,  Fig.  655,  after  Ramon  y 
Cajal.) 


THE     SYNAPSE  53 

that  offers  least  resistance.  The  ease  with  which  the 
synapses  may  be  crossed  determines  the  path,  and 
this  in  turn  is  determined  first  by  inheritance,  second 
by  use.  The  reflexes  of  the  cord  run  their  course  through 
synapses  already  prepared  at  birth.  The  course  of  an 
impulse  through  the  cortex  is  largely  controlled  by 
synapses  whose  degree  of  resistance  depends  upon  the 
frequency  with  which  they  have  been  used.  Evidently, 
then,  the  most  important  question  of  nervous  physiology 
for  the  psychologist  is  what  is  the  nature  of  the  synapse 
and  of  its  action. 

The  Amoeba  Theory  of  the  Synapse.  —  The  details 
of  the  mechanism  of  the  synapse  are  still  altogether 
lacking,  although  numerous  theories  have  been  developed 
to  explain  it.  All  agree  that  whenever  two  neurones 
are  active  at  the  same  time  some  change  is  induced 
in  the  synapse  that  makes  it  act  more  readily  later. 
The  two  neurones  become  more  nearly  a  single  unit  for 
action.  Two  suggestions  as  to  what  the  change  is  may 
be  mentioned  as  typical.  The  older,  and  in  many  ways 
the  simpler,  regards  the  neurones  as  living  organisms  that 
still  possess  at  their  extremities  the  power  of  motion  in- 
herent in  the  amceba-like  prototype.  When  both  cells 
are  active,  the  processes  extend  and  come  into  contact, 
and  the  chemical  action  of  the  one  in  some  way  excites 
a  similar  activity  in  the  other.  The  action  of  the  pro- 
cesses, particularly  of  the  dendrite,  leaves  behind  it  a 
disposition  to  act  again  more  easily  in  the  same  way. 
As  a  result  of  this  disposition,  the  same  extension  is 
repeated  on  suitable  occasion  and  the  connection  be- 
tween the  cells  and  their  simultaneous  action  is  renewed. 


54  THE    ESSENTIALS    OF   PSYCHOLOGY 

What  the  nature  of  the  change  may  be  is  not  made  very 
clear.  It  may  be  an  actual  physical  bond  that  persists 
when  the  end-brush  of  one  neurone  has  once  been 
brought  into  contact  with  the  dendrite  of  another,  or 
it  may  be  that  one  or  the  other  of  the  processes  takes 
on  a  habit  of  extending  in  the  way  that  brought  it  into 
contact  with  the  other.  The  original  obstruction  to 
the  transfer  of  the  action  from  one  neurone  to  another 
is  spatial,  and  this  original  gap  is  bridged  by  the  move- 
ment of  processes,  a  movement,  which  when  once  made, 
leaves  a  permanent  tendency  to  the  union  of  the  neu- 
rones. 

Sherrington's  Theory  of  the  Synapse.  —  The  more 
recent  theory,  proposed  by  Sherrington,  the  English 
physiologist,  is  that  the  synapse  opposes  the  passage 
of  an  excitation  in  much  the  same  way  that  a  mem- 
brane opposes  the  transfer  of  fluids.  At  first  this  resist- 
ance is  very  great,  but  it  is  lessened  with  each  act.  On 
this  theory  the  change  in  the  synapse  is  chemical  in 
character.  Here  again  the  exact  nature  of  the  change 
is  not  asserted.  On  either  theory  the  synapse  is  the 
point  where  action  leaves  its  impress  upon  the  nervous 
system,  —  it  is  here  that  learning  has  its  effect.  The 
change  that  comes  with  action  is  a  lessened  resistance  at 
the  synapse,  whether  it  be  due  to  the  coming  closer  of  the 
processes  or  to  a  chemical  change  that  makes  more  per- 
meable the  relatively  impermeable  membrane  that  at 
first  separates  the  neurones.  On  either  theory  it  is  pos- 
sible to  picture  the  synapse  as  a  valve  that  controls  the 
interaction  of  nerve  elements,  —  that  governs  the  passage 
of  the  nervous  impulse  from  unit  to  unit.  At  first  the 


THE    SYNAPSE  55 

valves  are  stiff  and  open  only  to  strong  currents ;  with 
use  they  work  more  easily  until  those  most  difficult  at 
birth  may  become  as  delicate  in  action  as  those  that  were 
at  birth  most  permeable.  It  should  be  emphasized  to 
avoid  giving  a  wrong  impression  that  there  is  no  real 
valve ;  it  is  only  that  the  action  is  like  what  might  be 
expected  were  there  a  valve  at  the  synapse.  As  the  out- 
come of  our  discussion,  we  have  a  picture  of  the  nervous 
system  as  a  mass  of  relatively  independent  amceba-like 
cells  that  are  held  in  a  definite  position  and  relation  to  one 
another  by  a  cage  of  bone.  At  the  beginning  certain  of 
the  neurones  constitute  a  path  for  an  impulse  from  sense- 
organs  to  muscles.  These  original  paths  are  few  and  make 
possible  only  the  activities  most  essential  to  the  continu- 
ance of  the  life  of  the  individual.  Additional  paths  of  con- 
nection are  formed  by  each  activity,  physical  and  mental. 
Whenever  any  two  neurones  chance  to  act  together  a 
connection  is  formed  between  them,  the  original  gap  is 
bridged,  and  they  come  to  form  part  of  a  new  pathway 
from  sense-organ  to  muscle.  This  holds  also  for  the 
action  of  the  neurones  within  the  cortex,  when  the 
learning  that  results  is  primarily  of  ideas  rather  than  of 
movements.  Learning,  whether  of  new  movements 
or  of  new  ideas,  is  a  process  of  making  easier  the  passage 
of  an  impulse  from  neurone  to  neurone  and  is  funda- 
mentally the  same  everywhere. 

Reflexes  Determined  by  the  Synapse.  —  When  the 
connections  in  the  nervous  system  have  once  been  formed, 
the  course  of  a  nervous  impulse  is  determined  by  the 
intensity  of  the  stimulus  and  the  openness  of  the  synapse. 
The  course  of  a  reflex  through  the  nervous  system  depends 


56  THE   ESSENTIALS   OF   PSYCHOLOGY 

upon  the  innate  connections  of  the  synapses.  In  the 
cord,  for  example,  a  slight  stimulus  on  the  hand  arouses 
the  muscles  of  that  arm ;  a  stronger  one  excites  the 
corresponding  member  of  the  opposite  side ;  still  stronger 
impressions  cause  contractions  in  the  legs,  and  finally 
contractions  will  spread  to  all  of  the  muscles  of  the 
trunk.  Translated  into  terms  of  neurones  and  synapses, 
this  indicates  that  the  synapse  which  opens  most  readily 
is  the  one  between  the  sensory  neurone  and  the  motor 
neurone  at  the  same  level  and  on  the  same  side  of  the 
cord.  Slight  stimuli  are  strong  enough  to  force  their 
way  across  this  gap.  As  the  stimulus  becomes  stronger, 
the  synapses  which  lead  to  the  opposite  side  of  the 
body  open,  then  those  that  lie  at  the  higher  and  lower 
levels.  The  course  of  the  impulse  and  the  selection  of 
the  movement  depend  altogether  upon  the  ease  with 
which  synapses  open  and  the  strength  of  the  stimulus. 
Habit  a  Change  in  the  Synapse.  —  The  same  factors 
determine  the  selection  hi  the  more  complicated  reac- 
tions of  the  higher  brain  centres.  In  man  the  action 
that  will  be  called  out  by  a  situation  depends  upon  the 
habits  he  has  formed,  and  these  in  turn  are  due  to  con- 
nections between  neurones  in  different  parts  of  the 
brain.  In  a  soldier  trained  to  answer  to  the  word  of 
command  the  readiest  response  is  to  obey,  however 
that  action  may  conflict  with  his  instincts.  The  synapses 
have  opened  so  frequently  between  the  centres  for  hear- 
ing and  the  movements  evoked  by  the  order  that  the 
stimulus  leads  to  action  at  once,  however  unfavourable 
the  other  circumstances.  In  these  responses,  too, 
stronger  stimuli  arouse  more  diffuse  responses.  Where 


HABIT   AND    THE    SYNAPSE  57 

a  single  command  when  in  ranks  meets  with  immediate 
response,  the  sudden  charge  of  an  enemy  when  the  ranks 
are  broken  and  the  men  are  in  disorder  may  cause  sudden 
diffuse  responses  that  will  overcome  the  effects  of  the 
long  drill.  Similarly,  in  a  game  of  baseball  the  habitual 
response  will  be  made  immediately  and  accurately 
when  the  stimulus  is  slight  and  the  circumstances  nor- 
mal, but  when  some  strong  stimulus  or  some  emotionally 
disturbing  event  takes  place  at  the  moment,  the  suitable 
habitual  response  is  frequently  lost  in  the  general  over- 
flow to  neighbouring  muscles.  The  ball  is  often  thrown 
over  the  first  baseman's  head  at  a  critical  moment. 
While  in  the  higher  habitual  responses  more  compli- 
cated factors  must  be  taken  into  consideration,  the  char- 
acter of  the  response  still  depends  upon  the  openness 
of  the  synapses  at  the  moment  and  the  intensity  of 
the  stimulus  or  its  appeal  to  the  individual.  In  essen- 
tials, the  response  of  the  higher  neurones  and  paths  of 
connection  follow  the  same  laws  as  the  lower. 

The  Formation  of  Habits.  —  One  of  the  most  impor- 
tant facts  that  can  be  referred  to  the  action  of  the  nervous 
system  is  the  formation  of  habits.  This,  as  has  been 
said,  is  due  primarily  to  the  opening  of  synapses  by 
use.  Habit,  whether  for  good  or  ill,  is  one  of  the  most 
striking  elements  in  any  explanation  of  behaviour.  As 
it  is  fundamental  for  many  of  the  psychological  explana- 
tions, we  may  begin  our  discussion  with  a  brief  sum- 
mary of  its  laws  and  applications.  In  popular  speech 
habit,  for  some  reason,  implies  bad  habit,  but  this  re- 
striction of  the  term  is  altogether  unjustifiable.  Absence 
of  habit  would  mean  complete  loss  of  efficiency.  Most  of 


58        THE  ESSENTIALS  OF  PSYCHOLOGY 

eating,  walking,  talking,  and  all  of  the  frequent  and  im- 
portant actions  of  everyday  life  are  habits  in  whole  or  in 
part.  Dressing  is  a  habit.  You  do  not  think  as  you  put 
on  your  garments.  Your  hands  find  their  way  to  the 
buttons  without  thought  and  without  your  being  con- 
scious that  they  are  moving.  The  tie  is  adjusted  with  no 
knowledge  of  the  separate  movements.  Were  you  asked 
to  describe  the  movements  made  in  tying  a  cravat,  you 
probably  could  not  do  so,  although  the  operation  is  run 
through  daily  without  mistake.  If  we  turn  from  a  dis- 
cussion of  the  omnipresence  of  habit  to  the  question  of 
what  goes  on  in  the  nervous  system  when  a  habit  is  ac- 
quired, we  get  back  to  our  problem  of  the  synapse  and 
its  relations.  Each  time  an  act  is  performed,  it  matters 
not  how,  there  is  some  change  in  the  synapses  between 
neurones.  The  effect  of  the  act  persists  and  becomes 
stronger  with  each  repetition.  After  several  repetitions 
the  connection  between  the  cells  becomes  so  close  that 
whenever  the  particular  sensory  cell  is  excited,  the  im- 
pulse spreads  to  the  motor  cells  active  with  it  before, 
and  the  neurones  grow  more  and  more  to  constitute  what 
is  practically  a  single  structure.  The  formation  of  habits 
is  thus  a  process  of  decreasing  the  resistance  of  the  syn- 
apses in  the  different  possible  paths  of  transmission.  Ul- 
timately it  is  due  to  a  change  of  some  kind  in  the  synapse. 
When  a  sensory  neurone  is  excited,  one  of  the  synapses  is 
more  open  than  the  others.  This  is  traversed  by  the 
impulse  and  the  corresponding  muscle  responds.  The 
opening  of  the  synapse  has  in  every  case  been  brought 
about  by  the  simultaneous  action  of  the  two  neurones. 
The  Omnipresence  of  Habit.  —  The  process  of  form- 


HABIT  59 

ing  a  habit  is  relatively  simple,  but  the  effect  of  habit  for- 
mation has  the  most  far-reaching  importance.  Every 
act  of  any  kind  is  the  forerunner  of  other  acts  of  the  same 
kind.  At  first  the  habit  is  easily  changed;  but  if  fre- 
.quently  persisted  in,  the  time  comes  when  that  movement 
must  be  made  whenever  the  particular  occasion  presents 
itself,  without  reference  to  the  other  circumstances  of  the 
moment.  Obviously  when  the  movements  are  repeated 
until  they  are  so  completely  fixed,  it  is  essential  that  the 
movements  chosen  for  fixation  shall  be  helpful  or  harm- 
less. The  useful  man  is  for  the  greater  part  marked  off 
from  the  useless  and  the  vicious  by  the  nature  of  his 
habits.  Industry  or  indolence,  good  temper  or  bad 
temper,  even  virtue  or  vice,  are  in  the  last  analysis 
largely  matters  of  habit.  One  forms  the  habit  of  work- 
ing at  certain  times  of  the  day,  and  soon  if  one  is  not 
busy  at  that  time  one  experiences  a  lively  sense  of  dis- 
comfort. Or,  on  the  contrary,  one  forms  the  habit  of 
loafing  all  day.  Work  then  becomes  distasteful  and 
indolent  irresponsibility  is  established.  Losing  .one's 
temper  is  largely  a  habit,  as  is  self-control.  Each  time 
one  is  provoked  by  a  trifle,  it  becomes  the  more  difficult 
to  look  calmly  at  an  unpleasant  episode ;  while  each  time 
one  remains  calm  under  difficult  circumstances,  strength 
is  gained  for  later  difficulties.  Similarly,  whenever 
temptation  is  resisted,  virtue  gains  a  victory;  when 
temptation  is  yielded  to,  new  weaknesses  develop. 
Frequent  yielding  makes  resistance  practically  im- 
possible. A  bank  president  of  established  morals  could 
no  more  step  out  and  pick  a  pocket  that  was  temptingly 
unprotected  than  he  could  fly.  The  habitual  drunkard 


60  THE   ESSENTIALS   OF   PSYCHOLOGY 

can  no  more  resist  the  invitation  to  have  a  glass  than  he 
can  resist  the  action  of  gravitation  while  falling  freely 
through  space.  Frequent  giving  in  has  entirely  de- 
stroyed his  original  freedom  of  choice. 

We  are  all  constantly  forging  chains  of  action  in  our. 
nervous  system  that  we  shall  never  be  able  to  break. 
Fortunate  is  the  man  whose  chains  are  all  suited  to  the 
life  he  is  compelled  to  live.  He  was  once  free  in  the 
sense  of  our  present  problem,  but  after  a  few  experiences 
he  becomes  bound  to  his  past  by  chains  that  only  the 
strongest  impulses  can  break.  Habits  are  not  restricted 
to  action,  but  show  themselves  even  in  the  features. 
Much  has  been  said,  particularly  in  semi-popular  writ- 
ing, of  the  ability  to  determine  character  from  the  face. 
Each  movement  of  the  muscles  of  the  face  has  left 
its  impress  upon  the  muscles  and  the  skin,  just  as 
each  action  has  left  its  impress  upon  the  nerve-cells. 
One  can  tell  at  a  glance  at  the  face,  even  in  repose,  what 
its  most  characteristic  responses  have  been  and  can  form 
some  idea  of  the  character  of  the  man,  of  the  effects  that 
have  been  left  by  the  same  actions  upon  the  nerve-cells 
which  show  themselves  when  the  man  is  called  upon 
to  act.  A  weak  man,  a  strong  man,  even  more  truly 
a  jovial  man  or  a  crabbed  man,  carries  the  marks  upon 
his  face.  These  marks  are  but  evidence  of  the  changes 
that  the  same  set  of  acts  has  left  upon  the  synapses  of  the 
nervous  system  everywhere  along  the  paths  of  action. 

Habits  Essential  to  Action.  —  Habit  not  only  limits 
choice  but  through  early  training  makes  choice  possible. 
The  adult  ordinarily  chooses  one  habit  rather  than  an- 
other ;  he  does  not  choose  between  some  habitual  action 


HABIT   AND    MEMORY  6l 

and  something  never  done  before.  What  has  never  been 
done  is  ordinarily  not  within  the  power  of  the  individual. 
For  example,  you  cannot  speak  the  Russian  word  for 
prince  and  could  not  if  some  one  should  first  pronounce 
the  word  for  you.  You  cannot  because  you  have  never 
developed  the  habit.  When  you  do  choose  to  speak  an 
English  word,  you  do  it  because  you  have  that  habit 
fully  developed.  Had  you  never  formed  habits  of 
speaking  you  would  be  as  powerless  in  English  as  in 
Russian.  As  all  of  our  intellectual  operations  are 
expressed  in  language,  habit  is  in  the  highest  sense  a 
powerful,  an  indispensable  tool  of  thinking.  But  that 
is  not  all.  If  you  eliminate  from  the  various  intellectual 
activities  all  that  belongs  to  habit,  most  of  the  higher 
mental  operations  become  impossible.  Habit,  like  fire, 
is  a  cruel  master  but  an  invaluable  servant.  Without 
it  all  action  would  cease  or  at  the  best  become  but  a 
painful  process  of  feeling  one's  way  through  even  the 
simplest  act. 

Association  of  Ideas  a  Form  of  Habit.  —  The  associa- 
tion of  ideas,  fundamental  for  thinking,  is  similar  to  habit. 
The  recall  of  any  memory  necessitates  the  stimulus  of 
some  earlier  connected  event.  An  old  experience  returns 
only  in  connection  with  some  other  event  now  revived 
in  consciousness.  On  the  nervous  side  this  means  that 
the  cells  in  the  cortex  corresponding  to  the  two  ideas 
have  been  active  together  and  that  the  resistance  of  the 
common  synapse  has  been  reduced  by  the  simultaneous 
action  of  the  two  neurones.  When  one  presents  itself, 
the  impulse  spreads  through  the  synapse  of  least  re- 
sistance to  the  related  cell  and  the  old  idea  is  recalled 


62  THE  ESSENTIALS   OF   PSYCHOLOGY 

All  recall  is  dependent  upon  the  connection  of  ideas,  and 
ideas  are  connected  only  as  the  neurones  are  united 
through  the  reduced  resistance  of  the  synapses.  The 
association  processes  are  thus  hi  every  particular  similar 
to  habits.  They  might  be  called  habits  of  neurones  in 
the  cortex.  The  only  difference  worth  emphasising  is  that 
in  this  case  there  is  no  movement  of  muscles  accom- 
panying the  activity  of  the  cortical  cells.  Even  this 
difference  is  not  always  present;  for  the  cortical  cells, 
whenever  active,  tend  to  call  out  movements,  often  very 
slight,  sometimes  nothing  more  than  the  tendency  to 
movement.  If  we  include  association  among  the  habits, 
we  may  say  with  complete  assurance  that  no  intellectual 
activity  of  any  kind  goes  on  except  on  the  basis  of  habit. 
Habit  and  association  are  the  two  fundamental  facts 
upon  which  all  of  our  activity,  mental  or  physical, 
depends.  That  either  should  be  lacking  is  inconceivable. 
Were  they  lacking,  man,  either  as  a  mental  or  as  a 
physical  being,  would  not  be  what  he  is. 

QUESTIONS 

1.  Describe  the  nervous  processes  that  accompany  seeing  a 
landscape.    How  are  they  different  from  the  perception? 

2.  When  the  idea  initiates  the  act  of  writing  a  description,  can 
you  say  that  the  idea  causes  the  movement  ? 

3.  Discuss  the  two  theories  of  changes  in  the  synapse. 

4.  Give  acts  that  are  determined  (a)  by  heredity,  (b)  by  use. 

5.  What  elements  of  character  may  depend  upon  habit? 

EXERCISES 

1 .  List  ten  acts  of  the  day  that  you  may  be  sure  are  habits. 

2.  Trace  the  different  steps  in  forming  the  habit  of  adjusting 
some  new  article  of  attire,  e.g.  adjusting  a  new  tie. 


HABIT  63 

3.   Try  to  break  some  undesirable  habit  and  keep  a  daily  record 
of  progress. 

REFERENCES 

JAMES  :  Principles  of  Psychology,  vol.  i,  ch.  iv. 

TITCHENER  :  Textbook  of  Psychology,  sec.  4. 

JUDD  :  Psychology,  pp.  61-64. 

PILLSBURY:  Attention,  pp.  129-225. 

McDouGALL :  Primer  of  Physiological  Psychology,  pp.  14-107. 

ANGELL  :  Psychology,  ch.  iii. 


CHAPTER  IV 
SENSATION 

SINCE  all  acts  and  all  conscious  processes  are  initiated 
by  sensory  stimulation,  it  is  necessary  to  have  a  full 
knowledge  of  the  different  stimuli  which  affect  man 
and  of  the  sensations  they  produce.  We  might  deter- 
mine without  the  use  of  introspection  what  stimuli 
are  effective  by  studying  the  responses  of  the  organ- 
ism. In  man,  however,  it  is  much  simpler  to  study 
the  direct  effects  in  consciousness.  This  has  the  added 
advantage  of  revealing  the  qualities  of  sensations. 
Knowledge  of  behaviour  is  dependent  upon  a  know- 
ledge of  the  stimuli,  and  sensations  are  interesting 
and  important  in  themselves.  We  may  turn  then  to 
our  first  task,  a  study  of  the  character  of  conscious- 
ness. 

Components  of  Consciousness.  —  We  may  follow  tra- 
dition and  begin  our  study  of  consciousness  by  attempt- 
ing to  discover  its  elementary  components.  At  this 
moment  the  consciousness  of  the  reader  is  made  up 
of  a  number  of  processes.  Experiences  are  received 
through  the  eyes  that  constitute  or  suggest  the  book 
with  its  physical  appearance.  At  the  same  time  you 
acquire  certain  elements  of  knowledge  from  the  words 
64 


SENSATION  65 

on  its  page.  Your  mind  wanders  now  and  again  to  the 
thought  of  the  game  you  would  like  to  be  having  or 
of  the  recitation  that  you  would  like  to  make  on  the 
morrow,  or  to  the  entertainment  of  the  evening,  or  to 
some  other  topic.  Accompanying  each  of  these  pro- 
cesses are  feelings  of  pleasure  or  displeasure,  and  in  many 
cases  emotions  of  greater  or  less  intensity.  Obviously 
even  the  simplest  consciousness  is  a  very  complex  affair. 
To  attempt  to  describe  or  to  classify  the  different  sorts  of 
consciousness  taken  in  this  concrete  way  would  evidently 
be  an  endless  task.  In  practice  the  undertaking  is  made 
easier  by  the  fact  that  the  memory  processes  and  the 
immediate  sensation  processes  have  approximately  the 
same  qualities.  A  remembered  or  imagined  red  is  of 
the  same  quality,  approximately,  as  the  red  that  is  seen 
directly.  Leaving  aside  the  feeling  processes  for  the 
moment,  we  may  say  that  the  qualities  of  consciousness 
are  the  qualities  of  sense.  Since  Locke  it  has  been  an 
axiom  of  psychology  that  there  is  nothing  in  mind  that 
was  not  previously  in  sense.  It  is  true  undoubtedly  that 
one  cannot  think  of  a  colour  that  has  never  been  seen. 
Try  to  picture  to  yourself  what  the  ultra-violet  waves 
would  be  like  to  an  eye  that  had  developed  a  capacity 
to  see  them,  and  you  will  find  that  each  colour  you  call 
up  is  compounded  out  of  those  already  familiar.  All 
-attempts  to  produce  an  imaginary  quality  that  has  not 
been  received  through  some  sense-organ  are  fruitless. 
Every  quality  of  memory  and  imagination  is  received 
through  the  senses.  New  things  may  be  compounded 
out  of  these  qualities,  but  the  number  of  qualities  is 
fixed  by  these  elementary  sensations.  Evidently,  then, 


66  THE  ESSENTIALS   OF  PSYCHOLOGY 

the  first  task  that  confronts  us  as  we  undertake  a  de- 
scription of  the  nature  of  consciousness  or  of  its  com- 
ponents is  to  determine  the  number  of  simple  sensations. 
We  approach  this  task  confident  that  its  solution  will 
determine,  not  merely  the  number  of  sensory  qualities, 
but  the  number  of  qualities  that  may  be  remembered  or 
imagined  as  well. 

Doctrine  of  Specific  Energies  of  Sensory  Ends.  —  The 
enumeration  of  sensory  qualities  is  not  so  simple  and  easy 
as  might  at  first  appear.  Whether  one  shall  call  each 
distinguishable  colour  in  the  spectrum  a  single  sensation 
or  shall  regard  them  all  as  compounded  of  a  few  simple 
qualities,  is  a  question  that  cannot  be  decided  by  direct 
observation.  A  theory  that  was  first  suggested  by 
Johannes  Miiller,  the  pioneer  m  modern  physiology, 
offers  perhaps  the  most  convenient  principle  to  guide  us 
in  our  task.  Briefly,  this  law  asserts  that  any  sense- 
organ  must  always  give  its  own  quality  of  sensation,  no 
matter  how  it  may  be  excited.  Simplest  evidence  of 
this  may  be  offered  by  pressing  the  eyeball  with  the 
finger.  You  will  notice  about  the  circle  of  pressure  a 
ring  of  light  of  a  quality  that  might  have  been  induced 
by  a  ray  of  light.  An  electric  current  passed  through 
the  eye  will  also  produce  a  visual  sensation,  as  will  jarring 
the  optical  apparatus  by  falling  ('  seeing  stars').  Con- 
versely, it  may  be  said  that  there  can  be  no  more  qualities 
of  sensation  than  there  are  different  kinds  of  sensory 
end  organs.  If  the  quality  of  the  sensation  depends  upon 
the  character  of  the  sense-organ  that  receives  it,  and  not 
upon  the  nature  of  the  stimulus,  the  number  of  sense 
qualities  must  be  as  great  as,  and  no  greater  than,  the 


SENSATION  DEPENDENT  ON  ORGAN        67 

number  of  sensory  ends.  Since  the  same  stimulus  often 
gives  different  results  upon  several  different  sense- 
organs,  the  difference  must  be  due  to  the  organ,  not  to 
the  stimulus.  Many  instances  may  be  cited.  A  vi- 
bration of  ether  excites  the  sensation  red  upon  the  retina 
of  the  eye,  a  sensation  of  warmth  upon  the  skin.  The 
electric  current  gives  a  different  sense  quality  for  each 
sense-organ,  —  pain  on  the  skin,  taste  on  the  tongue, 
and  so  on.  If  we  accept  this  law,  it  follows  that  we  can 
determine  the  number  of  different  kinds  of  sensation  if 
we  can  discover  the  number  of  distinct  sensory  end 
organs. 

The  Development  of  Sensations.  —  The  development 
of  the  sense  qualities  depends  upon  and  goes  hand  in 
hand  with  the  development  of  the  sensory  endings.  In 
the  simplest  organisms  there  is  no  differentiation  of  sen- 
sory tissue,  and  consciousness  perhaps  shows  no  dif- 
ferences whatever.  All  stimuli  give  rise  to  exactly  the 
same  effect.  Taste  is  not  different  from  touch,  sight 
from  hearing,  —  if  hearing  be  present  at  all.  All  forms 
of  stimuli  excite  the  same  organ  and  in  consequence 
must  give  the  same  effect.  As  differentiation  takes 
place  in  the  animal  series,  new  organs  are  developed  and 
new  sense  qualities  make  their  appearance.  At  the  level 
of  insects  most  of  the  senses  found  in  man  are  pretty 
well  differentiated.  Even  in  man,  however,  not  all  of 
the  physical  stimuli  have  corresponding  sensations. 
The  electric  and  magnetic  forces  have  no  sense-organs 
and  are  not  recognised  as  separate  qualities.  For  that 
reason,  too,  knowledge  of  electrical  and  magnetic 
phenomena  developed  relatively  late.  Indirect  evi- 


68  THE  ESSENTIALS   OF  PSYCHOLOGY 

dence  obtained  through  the  other  senses  alone  gives 
knowledge  of  their  existence.  Our  problem  in  this 
chapter  is  to  determine  the  number  of  different  kinds  of 
sensory  ends  that  the  human  organism  presents  to  the  ex- 
ternal world,  confident  that  this  will  also  give  the  number 
of  distinct  conscious  qualities. 

Sensations  of  Temperature.  —  We  may  begin  with 
the  sensations  derived  from  the  skin,  since  the  skin  is 
probably  the  simplest  of  the  sense-organs,  although  far 
more  complex  than  one  is  inclined  to  believe.  The 
ordinary  assumption  seems  to  be  that  the  skin  is  a  com- 
paratively homogeneous  surface  with  but  one  sense 
quality.  Recent  investigation,  beginning  in  the  early 
eighties  of  the  last  century,  has  shown  that  the  skin  has 
four  senses  and  that  each  is  distinct  in  quality  and  in 
sensory  ending.  Two  of  these  respond  primarily  to 
mechanical  stimulation,  two  to  temperature.  The 
mechanical  senses  are  pressure  and  pain,  the  temperature 
senses  are  warmth  and  cold.  Evidence  for  the  two 
temperature  senses  is  most  readily  obtained  by  the 
beginner.  If  one  will  but  run  over  the  skin  with  the 
point  of  a  rod  heated  above  the  body  temperature,  one 
will  notice  that  the  rod  feels  warm  only  here  and  there 
at  points  well  separated.  These  spots  were  found  by 
von  Frey  to  average  about  one  and  one-half  to  the  square 
centimetre.  If  the  rod  be  cooled  below  the  temperature 
of  the  skin,  cold  is  noticed  at  many  more  spots,  about 
thirteen  to  the  square  centimetre,  but  still  wide  areas 
without  temperature  sensations  intervene.  While,  then, 
the  physicist  assures  us  that  cold  is  nothing  but  the 
absence  of  heat  so  far  as  energy  is  concerned,  it  is  un- 


SENSATIONS    OF    TEMPERATURE 


69 


doubted  that,  physiologically  and  psychologically,  cold 
is  just  as  truly  a  distinct  sensation  as  warmth.  Not  only 
is  it  proved  by  mapping  the  spots  that  the  temperature 
senses  are  distinct,  but  the  result  is  confirmed  by  a  num- 


/**' 
f  * 


FIG.  ii.  —  Map  of  warm  and  cold  spots  on  volar  surface  of  forearm.  The  dots 
represent  warm  spots  as  tested  at  a  temperature  of  41  "-48°  C.  ;  the  crosses, 
cold  spots  as  tested  at  10°.  (From  Ho  well,  after  von  Frey.) 


ber  of  related  facts,  (i)  Stimulation  of  a  well-marked 
cold  spot  always  gives  cold  only,  no  matter  what  the 
source.  Pressure,  the  electric  current,  even  the  warmth 
obtained  by  concentrating  the  sun's  rays  upon  the  spot 
by  a  small  lens,  all  give  the  same  sensation  of  cold. 


70  THE   ESSENTIALS   OF   PSYCHOLOGY 

Warm  spots  may  also  be  aroused  by  inadequate  stimuli 
but  they  require  greater  intensity  than  the  cold  spots. 
(2)  Certain  parts  of  the  body,  the  cornea  of  the  eye, 
e.g.,  lack  warm  spots  altogether,  and  there  are  relatively 
large  areas  where  cold  spots  are  lacking.  (3)  Certain 
chemicals,  e.g.  menthol  for  cold,  carbon  dioxide  for 
warm,  will  excite  one  sort  of  spot,  but  not  the  other. 
All  these  facts  go  to  show  that  cold  and  warmth  are  inde- 
pendent senses  with  independent  nerve  ends  in  the  skin. 
Physiological  Temperature  Scale.  —  The  response  of 
the  nerve  ends  to  the  different  changes  in  temperature 
is  indicated  in  the  accompanying  diagram.  The  physi- 
ological zero  point  lies  somewhere  in  the  neighbourhood 
of  30°  C.  The  variation  is  from  28°  or  below  to  34°  or 
above,  according  to  the  temperature  to  which  the  body 
has  been  adjusted.  At  any  one  time  the  limit  will  be 
only  a  fraction  of  a  degree.  Below  this  point  all  tem- 
peratures excite  the  cold  organ ;  above,  all  excite  the 
organ  of  warmth.  Very  low  temperatures,  from  12° 
downward,  also  excite  the  nerves  of  pain  which  give  the 
sensation  of  burning  or  biting  cold.  Above  the  neutral 
point,  at  about  45°  C.,  warm  becomes  hot.  In  con- 
sciousness it  is  marked  off  from  warm  by  a  very  sharp 
line.  Physiologically,  the  difference  is  due  to  the 
presence  of  the  sensation  of  cold.  Hot  is  a  compound 
of  warm  and  cold.  This  excitation  of  cold  spots  by  heat 
has  been  called  the  paradoxical  cold  sensation.  Beyond 
this,  at  some  50°  C.,  pain  is  also  aroused  and  gives  burn- 
ing heat.  All  the  temperature  effects  are  produced  by 
combinations  of  the  excitations  of  the  three  sense  endings 
of  cold,  warmth,  and  pain. 


SENSATIONS   OF   PRESSURE 


\ 


V    i 


I       I  1 

FIG.  12.  —  Shows  the  sense-organs  stimulated,  and  approximate  degree  of  stimu- 
lation at  the  different  temperatures.  The  figures  on  the  base  Hne  indicate  the 
temperature  in  centigrade,  the  height  of  the  line  the  amount  of  stimulation. 
(After  von  Frey :  ' Vorlesungen  iiber  Physiologic,'  Fig.  50.) 


Cutaneous  Sensations  from  Mechanical  Stimuli.  — 
Two  sense  qualities  may  be  excited  mechanically,  pres- 
sure and  pain.  Somewhat  the  same  differentiation 
must  be  made  between  them  as  between  the  tempera- 
ture senses.  Gentle  pressure  upon  the  skin  with  a 
sharply  pointed  wooden  rod  or  a  short  hair  is  felt  only 
here  and  there.  These  points  are  known  as  the  pressure 
spots.  They  are  found  closer  together  on  the  average 
than  either  class  of  temperature  spots.  They  vary  from 
about  nine  to  some  three  hundred  to  the  centimetre. 


72         THE  ESSENTIALS  OF  PSYCHOLOGY 

These  pressure  spots  are  relatively  easy  to  excite,  —  they 
are  affected  by  hairs  that  exert  a  pressure  of  little  more 
than  a  milligram.  The  pain  spots  are  much  closer 


FIG.  13.  —  Nerve  endings  in  skin  and  about  hair  follicles,  (c)  the  most  super- 
ficial plexus  of  fibres  in  the  skin,  free  nerve  endings  still  nearer  the  surface ; 
(A)  the  hair  with  nerves  about  root.  (From  Barker,  Fig.  227,  after  Retzdus.) 


SENSE-ORGANS   IN   THE   SKIN  73 

together  and  require  greater  pressure  for  their  stimula- 
tion. They  are  most  easily  found  by  pressing  upon  the 
different  points  on  the  skin  with  a  well-sharpened  horse- 
hair. It  has  been  shown  that  200  or  more  points  to 
the  centimetre  give  rise  to  the  pain  sensations.  That 
pain  is  not  merely  a  more  intense  pressure,  as  was 
thought  for  a  long  time,  is  proved  (i)  by  the  fact 
that  a  pressure  spot  always  responds  more  quickly 
than  a  pain  spot,  and  (2)  that  certain  parts  of  the 
body  are  sensitive  to  pressure  but  not  to  pain,  e.g. 
the  inner  membrane  of  the  cheek,  while  the  cornea  of 
the  eye  always  responds  with  pain,  never  with  pres- 
sure, no  matter  how  slight  the  excitation.  Again,  (3) 
certain  drugs  destroy  one  sense  quality  and  leave  the 
other  unaffected,  e.g.  cocaine  when  first  applied  de- 
stroys the  sensitiveness  to  pain  but  not  to  pressure; 
a  rare  drug,  saponin,  destroys  sensitiveness  to  pressure 
but  not  to  pain.  It  is  now  generally  held  that  pain 
and  pressure  are  distinct  senses  with  distinct  kinds  of 
sensory  endings  in  the  skin. 

The  Organs  of  Cutaneous  Sensation.  —  Pressure  and 
pain  may  with  some  certainty  be  referred  to  particular 
sense-organs.  The  nerves  of  pressure  for  the  greater  part 
of  the  body  are  the  nerves  at  the  roots  of  the  hairs,  as 
illustrated  in  the  accompanying  diagram.  On  the  palms 
of  the  hands  and  the  soles  of  the  feet  where  hairs  are 
lacking,  the  organ  of  pressure  is  the  touch  corpuscle  of 
Meissner  found  in  the  papillae  of  the  skin.  (Figure  14.) 
The  nerves  of  pain  are  the  free  nerve  ends  that  extend 
into  the  outer  skin.  They  too  may  be  seen  in  Figure  13. 
That  pain  has  a  very  superficial  organ  is  evident  from 


74 


THE  ESSENTIALS   OF   PSYCHOLOGY 


the  fact  that  an  acid  will  give  rise  to  pain  before  it  affects 
any  other  of  the  sense  ends.  It  needs  only  to  eat  into 
the  most  superficial  layer  of  the  skin,  and  the  sensation 
of  pain  is  aroused.  The  organs  of  warmth  and  cold  have 
not  been  made  out  with  any  certainty.  The  skin,  then, 
is  not  a  single  sense-organ,  but  a  mosaic  in  which  four 
separate  senses  may  be  distinguished,  each  with  a  special 
end-organ.  These  are  pressure, 
pain,  warmth,  and  cold.  With 
their  combinations  they  give  rise 
to  all  knowledge  of  the  outer  world 
obtained  through  the  skin. 

The  Gustatory  Sensations.  — 
The  principles  established  for 
touch  can  be  readily  transferred 
to  taste.  As  every  one  knows, 
the  chief  organ  of  taste  is  the 
tongue.  More  particularly  the 
sense  endings  of  taste  are  to  be 
found  on  the  sides  of  the  foliate, 
the  fungiform,  and  the  circum- 
vallate  papillae  on  the  tongue. 
Essentially  the  papillae  are  folds 
of  skin  on  the  surface  of  the 
tongue.  The  sense  endings  proper  are  the  taste  beakers 
which  are  arranged  along  the  sides  of  the  depressions 
formed  by  the  papillae.  The  beaker  itself,  as  may  be  seen 
from  the  diagram,  is  a  group  of  nerve  ends  interspersed 
with  supporting  cells.  The  whole  looks  not  unlike  a  flower 
bud.  The  papillae  are  scattered  fairly  thickly  over  the 
tip,  sides,  and  back  of  the  tongue.  They  can  be  seen 


FIG.  14.  —  Tactile  corpuscle 
of  Meissner  from  the  skin 
of  toe.  (N)  nerve  fibre. 
(From  Barker,  Fig.  242, 
after  Schiefferdecker.) 


SENSATIONS   OF   TASTE 


75 


on  the  tip  of  the  tongue  as  little  bright  red  depressions. 
Four  separate  taste  qualities  are  distinguished, — 
sweet,  salt,  sour,  and  bitter.  The  different  qualities 
cannot  be  so  easily  connected  with  different  spots  on  the 
tongue  as  can  the  touch  qualities  with  spots  on  the  skin. 


Subyemmal    cell 


InUrgemmttl  fibrils 

FIG.  15.  —  Taste-buds  and  endings  of  gustatory  nerves,  (a)  shows  taste  cells 
about  a  central  supporting  cell;  (6)  fibrils  around  and  between  the  taste- 
buds.  (From  Barker,  Fig.  348.) 

The  taste-buds  are  well  concealed  in  the  papillae  and 
a  single  papilla  often  possesses  more  than  one  quality. 
It  is  assumed,  however,  that  each  taste  beaker  responds 
to  but  one  quality,  although  several  beakers  of  different 
kinds  may  be  present  in  the  same  papilla.  In  general, 


76  THE  ESSENTIALS   OF  PSYCHOLOGY 

sweet  is  perceived  on  the  tip,  sour  on  the  sides  of  the 
tongue,  bitter  on  the  back,  while  salt  is  pretty  evenly 
distributed.  At  the  most  this  arrangement  is  only 
partly  carried  out,  and  there  are  many  exceptions.  The 
best  evidence  for  the  doctrine  of  specific  energies  is  the 
fact  that  different  drugs  dull  or  destroy  the  capacity 
to  discriminate  different  tastes  in  different  degrees. 
Cocaine,  for  example,  first  destroys  the  sensitiveness  to 
bitter  and  affects  the  other  tastes  more  slowly.  Gym- 
nemic  acid  first  destroys  the  sensitiveness  to  sweet. 
The  time  required  for  the  nerves  to  respond  is  also  dif- 
ferent for  each  taste.  These  facts  together  seem  sufficient 
to  justify  the  statement  that  the  four  taste  qualities  have 
each  a  special  sort  of  taste  beaker,  although  several 
different  sorts  of  beakers  are  usually  found  in  a  single 
papilla. 

Combination  of  Taste  with  Other  Sensations.  —  One 
may  be  inclined  to  question  the  statement  that  only  four 
taste  qualities  can  be  distinguished,  for  certainly  or- 
dinary experience  seems  to  show  a  large  number.  This 
objection  must  be  admitted.  The  other  qualities  are, 
however,  not  tastes  but  additions  from  other  senses. 
The  most  evident  are  the  ordinary  cutaneous  sensations. 
Temperature  seems  to  modify  taste,  as  is  seen  in  the 
peculiar  effect  of  the  cold  of  ice  cream  or  the  heat  of 
coffee.  Melted  cream  seems  to  have  a  different  taste 
from  the  frozen;  cold  or  lukewarm  coffee,  from  hot. 
Roughness  or  smoothness  adds  a  quality  not  easily 
distinguished  from  taste.  Witness  the  difference  be- 
tween granulated  and  pulverised  sugar.  Other  instances 
will  be  recalled  by  the  practical  housewife.  By  far  the 


OLFACTORY   SENSATIONS  77 

most  important  additions  are  those  that  are  made  by 
smell.  Most  of  what  we  seem  to  taste  we  really  smell. 
All  of  the  delicate  tastes,  so  called,  are  largely  odours 
that  reach  the  sensory  region  in  the  nose  by  way  of  the 
inner  air  passages.  That  much  of  the  taste  of  food  is 
really  received  through  the  nose  is  evident  from  the 
fact  that  a  cold  destroys  nearly  all  taste.  Moreover,  if 
the  nostrils  be  closed,  substances  will  be  confused  that 
ordinarily  are  easily  distinguished.  Cinnamon  is  said 
not  to  be  distinguishable  from  flour  under  these  cir- 
cumstances. In  short,  in  what  is  ordinarily  called  taste 
we  have  a  mixture  of  the  four  simple  tastes  with  the 
qualities  of  cutaneous  sensation  and  with  odour.  The 
stimulus  for  taste  is  some  chemical  dissolved  in  a  liquid 
and  brought  into  contact  with  the  taste-buds  by  being 
caught  in  the  papillae.  A  substance  to  be  tasted  must  be 
dissolved  either  before  it  is  taken  into  the  mouth  or  by 
the  saliva. 

Sensations  of  Smell.  —  Of  the  sense  of  smell  we  know 
practically  nothing.  All  that  can  be  determined  is  that 
the  organ  of  smell  is  the  olfactory  membrane  in  the  upper 
nasal  cavity.  The  sense  nerves  are  simple  cells  with 
hairlike  projections  that  come  to  the  surface  of  the  mem- 
brane between  supporting  cells.  In  their  structure  they 
are  the  simplest  of  the  sense-organs.  The  stimulus  for 
odours  is  some  chemical  substance  carried  to  the  olfactory 
membrane  in  particles.  It  produces  some  chemical 
change  in  the  sense  ending  and  this  starts  the  nervous 
impulse  toward  the  brain. 

No  definite  answer  can  be  given  to  the  question  of  the 
number  of  different  organs  and  the  number  of  different 


78  THE  ESSENTIALS   OF  PSYCHOLOGY 

olfactory  qualities.  Zwaardemaker  has  suggested  that 
there  are  nine,  but  his  results  cannot  be  accepted  as 
conclusive.  Certain  facts  connected  with  pathology  and 
with  fatigue  indicate  that  there  are  different  organs  for 
the  different  odours.  In  diseased  conditions  a  patient 


FlG.  1 6.  —  Scheme  of  the  olfactory  apparatus  of  mammals.  (D)  the  olfactory 
membrane;  (&)  the  olfactory  neurone.  Above  are  shown  the  more  central 
neurones  connecting  with  the  olfactory  lobe.  (From  Barker,  after  Ramon  y 
Cajal.) 

may  lack  one  class  of  odours  alone.  Also  the  nose  may 
be  fatigued  for  one  odour  and  remain  sensitive  to  others. 
After  one  has  smelled  camphor  for  some  time,  alcohol 
will  not  be  noticed,  but  iodine  will  still  have  its  usual 
effect.  While  these  experiments  are  suggestive  of  the 


AUDITION  79 

presence  of  distinct  sense-organs  for  different  odours, 
they  have  not  been  carried  far  enough  to  determine  the 
number  of  qualities.  The  uncertainties  of  science  are 
reflected  in  the  popular  speech.  There  are  no  names  for 
odours  other  than  those  of  the  objects  that  give  rise  to 
them.  The  difficulty  is  increased  by  the  fact  that 
tactual  and  taste  qualities  mix  with  the  olfactory.  The 
sweet  odour  of  chloroform  is  really  a  taste.  The  odour 
of  ammonia  is  largely  pain,  and  the  resulting  holding 
of  the  breath  adds  a  feeling  of  suffocation.  Zwaarde- 
maker  classes  as  nauseating  certain  odours  that  receive 
their  peculiar  quality  from  the  incipient  retching  re- 
flexes excited  in  the  throat.  Of  smell  we  know  only 
that  the  organ  is  simple  and  has  its  seat  in  the  upper 
nasal  passages,  that  there  are  distinguishable  qualities, 
but  that  their  number  is  uncertain,  and  that  smell  com- 
bines with  taste  and  tactual  impressions  to  produce  very 
complex  fusions. 

Hearing.  —  The  first  of  the  so-called  higher  senses  is 
hearing.  It  is  higher  in  its  importance  for  the  mental 
life,  in  the  degree  of  complexity  of  the  organ,  and  in  the 
richness  of  its  qualities.  In  each  of  the  higher  senses 
we  must  consider  the  sense  excitation  at  three  different 
stages:  (a)  the  physical  stimulus,  (b)  the  change 
excited  in  the  sense-organ,  and  (c)  the  resulting  con- 
scious qualities.  The  stimulus  for  hearing,  physics 
teaches,  is  vibration  in  the  air.  The  wave-lengths  vary 
in  three  ways:  in  the  rate  of  their  vibration,  in  the 
distance  through  which  the  particles  vibrate  or  the 
amplitude  of  vibration,  and  in  the  form  or  complexity 
of  the  wave.  The  rate  of  vibration  corresponds  to  the 


8o  THE  ESSENTIALS   OF  PSYCHOLOGY 

pitch  of  the  tone,  the  amplitude  corresponds  to  the 
intensity  of  the  tone,  and  the  form  to  the  timbre 
or  tone  colour.  The  form  of  the  wave  gives  the  tone 
of  each  instrument  its  character,  e.g.  [the  C  of  the 
violin  differs  from  the  C  of  the  piano  only  in  its  wave 
form. 

Structure  of  the  Ear.  —  The  organ  of  hearing  is  the  ear. 
The  ear  is  for  convenience  of  description  divided  into 
three  parts,  —  the  external  ear,  the  middle  ear  or  drum, 
and  the  inner  ear  or  labyrinth.  The  outer  ear  is  the 
trumpet  of  cartilage,  popularly  called  the  ear,  together 
with  the  tube  that  extends  into  the  skull.  Its  only 
function  is  to  gather  the  sound-waves  and  bring  them  to 
the  drum.  The  middle  ear  extends  from  the  membrane 
of  the  drum  backward  to  the  bony  inner  ear.  In  es- 
sentials the  middle  ear  is  an  irregularly  shaped  hollow 
in  the  skull  separated  from  the  outer  world  by  the 
drum  membrane,  and  connected  with  the  throat  by  the 
Eustachian  tube.  So  far  as  it  concerns  us,  it  is  a  cavity 
across  which  extends  a  chain  of  three  bones,  the  hammer, 
anvil,  and  stirrup,  from  the  membrane  of  the  drum  to 
the  oval  window  of  the  labyrinth.  The  drum  head  is 
a  membrane  stretched  obliquely  across  the  opening  of 
the  ear.  On  its  inner  surface  is  the  handle  of  the  ham- 
mer. The  head  of  the  hammer  fits  into  the  anvil,  and 
this  is  attached  to  the  head  of  the  stirrup.  Each  bone 
receives  its  name  from  its  shape.  When  a  sound-wave 
strikes  against  the  membrane  of  the  drum,  the  mem- 
brane is  forced  inward  slightly,  and  this  inward  motion 
carries  the  handle  of  the  hammer  with  it.  The  hammer 
and  the  other  bones  revolve  about  a  ligament  attached 


STRUCTURE    OF    THE   EAR 


81 


to  the  top  of  the  middle  ear.  The  pressure  of  the  air 
wave  upon  the  drum  membrane  turns  the  bones  about 
this  as  a  pivot,  and  the  stirrup  communicates  the  motion 
to  the  liquid  of  the  inner  ear.  When  the  pressure  of 
the  air  is  relaxed,  the  membrane  of  the  drum  returns 


FIG.  17.  —  Diagram  of  ear,  showing  relation  of  parts.  (If)  and  (G)  external 
ear;  (P)  middle  ear  with  small  bones ;  (5)  cochlea;  (A)  auditory  nerve;  (R) 
Eustachian  tube.  (From  Professor  Calkins,  Fig.  15,  after  Martin-Czermak.) 
In  this  cut  the  cochlea  is  turned  90°  from  its  true  position  for  convenience 
of  representation.  The  top  of  the  cochlea  should  be  turned  toward  the 
observer. 

to  its  original  position  or  a  little  beyond  and  carries  with 
it  the  chain  of  bones  and  the  foot  of  the  stirrup.  The 
foot  of  the  stirrup  fits  closely  into  the  oval  window  of 
the  inner  ear,  and  the  joint  is  closed  by  a  delicate  mem- 
brane that  makes  the  whole  water-tight.  While  this 

G 


THE   ESSENTIALS   OF   PSYCHOLOGY 


FIG.  18.  —  Section  of  tube  of  cochlea.  (Lam.  sp.)  lamina  spiralis,  through  which 
the  nerve  passes;  (m.b.)  basilar  membrane;  (Org.  C.)  organ  of  Corti;  (m.t.) 
tectorial  membrane.  (From  Professor  Calkins,  Fig.  17,  after  Foster.) 

is  the  ordinary  course  of  stimulation,  high  tones  appar- 
ently pass  through  the  bones  of  the  head.  In  some 
cases,  too,  hearing  is  normal  when  the  bones  have  been 
destroyed  by  disease. 


SENSATIONS   OF  HEARING  83 

The   Mechanics   of   the   Cochlear   Vibration.  —  The 

movement  of  the  stirrup  transmits  the  excitation  to  the 
inner  ear,  the  point  where  hearing  as  a  nervous  process 
begins.  The  auditory  portion  of  the  ear  is  the  cochlea. 
The  cochlea,  as  its  name  implies,  is  a  tube  coiled  up  like 
a  snaii  shell  for  two  and  a  half  turns.  It  is  divided  down 
the  middle  by  a  ridge  of  bone  and  a  thin  membrane 
known  as  the  basilar  membrane.  Figure  18  shows  a 
cross  section  of  the  tube  of  the  cochlea.  One  of  the 
first  questions  in  connection  with  the  action  of  the  ear 
is  how  it  is  possible  for  the  vibrations  of  the  stirrup  and 
of  the  oval  window  to  have  any  effect  upon  the  liquid 
that  fills  the  cochlea  and  the  inner  ear.  The  vibration 
of  the  liquid  is  rendered  possible  by  the  round  window, 
an  opening  in  the  bony  wall,  closed  by  a  delicate  mem- 
brane. It  is  below  the  oval  window,  at  the  point  marked 
Pt  in  Figure  17.  Pressure  upon  the  stirrup  at  the  oval 
window  is  transmitted  through  the  entire  length  of  the 
cochlear  fluid  to  the  round  window.  The  membrane 
gives  and  thus  makes  possible  the  vibration  of  the  fluid. 
The  vibrations  of  the  outer  air  push  the  membrane  of 
the  drum  in  and  out.  The  drum  head  starts  an  oscil- 
lation of  the  chain  of  bones,  the  stirrup  presses  against 
the  liquid  of  the  inner  ear,  and  this  is  permitted  to 
vibrate  by  the  delicate  membrane  of  the  round  window. 
The  Helmholtz  Theory  of  Hearing.  —  All  of  this  is 
only  preparation  for  the  excitation  of  the  nerve  of  hear- 
ing. The  nerve  of  hearing  ends  in  connection  with  the 
fibres  of  the  basilar  membrane.  The  exact  connection 
between  the  nerve  fibres  and  the  fibres  of  the  basilar 
membrane  has  not  been  altogether  made  out,  but  nerve 


84  THE   ESSENTIALS    OF   PSYCHOLOGY 

fibres  come  through  the  spiral  of  bone  and  end  in  con- 
nection with  hairs  upon  the  basilar  membrane.  These 
hairs  are  excited  in  some  way  by  the  vibrations  of  the 
basilar  membrane  and  they,  in  turn,  excite  the  auditory 
nerve.  The  most  generally  accepted  theory  of  hearing 
was  suggested  by  Helmholtz,  who  regarded  the  basilar 
membrane  as  a  series  of  strings  like  the  strings  of  a  piano. 
Each  string  is  tuned  to  some  one  of  the  audible  tones. 
Whenever  the  tone  to  which  a  string  is  tuned  is  repre- 
sented in  the  vibrations  of  the  liquid  of  the  inner  ear, 
that  string  is  thrown  into  sympathetic  vibration.  The 
vibration  of  the  fibre  starts  a  nervous  impulse  in  the  nerve 
connected  with  it,  and  this  impulse  is  transmitted  to  the 
brain  through  a  series  of  neurones.  The  sensation  of 
sound  makes  its  appearance  upon  the  excitation  of  cells 
in  the  temporal  lobes  of  the  cortex.  The  process  of 
exciting  a  vibration  in  the  fibre  is  very  similar  to  that 
which  accompanies  speaking  into  a  piano  when  the  keys 
are  held  down.  When  you  speak,  the  strings  tuned  to 
your  voice  are  excited  sympathetically  and  can  be  heard 
after  you  finish  speaking.  In  the  basilar  membrane  the 
fibres  are  said  to  number  between  eighteen  and  twenty 
thousand,  while  the  tones  that  can  be  distinguished  by 
the  ordinary  ear  have  been  computed  at  approximately 
eleven  thousand.  The  number  of  strings  is  then  suffi- 
cient for  the  tones  that  may  be  heard.  The  case  for  the 
Helmholtz  theory  is  strengthened  by  the  limited  number 
of  tones  that  may  be  appreciated.  The  upper  and  lower 
limit  of  hearing  may  be  explained  by  the  limited  number 
of  fibres.  The  lowest  tone  that  may  be  heard  has  ap- 
proximately sixteen  vibrations  per  second ;  the  highest 


SENSATIONS   OF   HEARING  85 

varies  from  about  thirty  thousand  to  forty-five  thousand 
per  second.  Another  strong  bit  of  evidence  for  the 
theory  is  that  after  death  there  have  been  found  in 
individuals,  who  were  deaf  to  certain  notes  of  the  scale 
only,  regions  of  the  basilar  membrane  in  which  disease 
had  destroyed  the  fibres.  The  objections  to  the  Helm- 
holtz  theory  are  to  be  found  primarily  in  the  physical 
improbability  that  fibres  as  short  as  those  of  the  basilar 
membrane  from  0.48  to  0.04  mm.  in  length,  should  be 
able  to  vibrate  in  sympathy  with  the  lower  tones  that 
are  heard.  Several  authorities  have  asserted  that  the 
fibres  are  too  rigid  to  vibrate  to  faint  tones.  Whatever 
the  objections,  the  Helmholtz  theory  is  the  one  at 
present  generally  accepted. 

Complex  Tones  and  Noises.  —  If  we  may  assume  that 
the  simple  tone  corresponds  to  the  excitation  of  a  single 
fibre  of  the  basilar  membrane,  it  seems  probable  that  the 
complex  tones  are  due  to  the  excitation  of  several  fibres. 
A  complex  tone  like  a  note  of  the  piano  would  be  made 
up  of  one  tone,  the  fundamental,  and  of  others  of  a  rate 
two,  three,  four,  and  other  even  multiples  of  that  rate. 
The  timbre  of  the  tone  varies  with  the  number  and  char- 
acter of  the  overtones.  In  the  violin  tone  the  high  over- 
tones predominate;  in  the  piano  tone  the  overtones 
decrease  in  strength  as  they  increase  in  pitch.  In  the 
ear  each  of  these  overtones  is  taken  up  by  a  different 
fibre  and  is  carried  to  the  cortex  separately.  In  con- 
sciousness they  ordinarily  fuse  to  form  a  single  quality, 
although  by  close  attention  the  elements  may  be  dis- 
tinguished. What  then  in  the  air  is  fused  into  a  single 
wave  of  characteristic  form  is  analysed  by  the  basilar 


86  THE  ESSENTIALS   OF  PSYCHOLOGY 

membrane  into  its  separate  elements  and  reunited  in 
consciousness  to  form  a  complex  tone.  Noises  of  the 
continuous  kind  may  be  regarded  as  very  complex  tones 
made  up  of  many  vibration  rates  that  have  no  simple 
arithmetical  relation  to  each  other.  Each  is  received 
by  a  separate  fibre  and  transmitted  to  the  cortex,  where 
the  result  is  a  jumble  of  sensations.  The  single  crash 
or  crack,  the  second  form  of  noise,  arises  from  a  twitch 
of  the  fibre  of  the  membrane  that  does  not  persist  long 
enough  to  give  a  full  tone.  Any  tone  will  give  a  single 
puff  of  noise  if  it  is  permitted  to  affect  the  ear  during 
but  two  full  vibrations.  In  either  case  the  noise  is  heard 
by  the  same  part  of  the  ear  that  perceives  the  tone,  the 
fibres  of  the  basilar  membrane  in  the  cochlea. 

Summary.  —  In  short,  vibration  in  the  air  is  received 
by  the  membrane  of  the  drum  and  is  transmitted  to  the 
oval  window  through  the  chain  of  small  bones.  At  the 
oval  window  the  oscillations  of  the  bones  produce  vibra- 
tions in  the  liquid  of  the  inner  ear.  The  several  tones  are 
received  by  the  different  fibres  of  the  basilar  membrane 
attuned  to  them.  The  vibration  of  the  fibres  excites 
a  change  in  the  auditory  nerve,  and  the  nervous  impulse 
is  carried  to  the  cortex  where  sensation  arises.  It  is 
still  a  question  whether  we  are  to  assume  that  each  fibre 
has  its  own  quality  of  sensation  and  that  there  are 
therefore  eleven  thousand  distinct  sensations  and  eleven 
thousand  distinct  sorts  of  nerve  fibre,  or  whether  the 
different  fibres  are  grouped  in  some  way  in  larger  classes. 
The  objection  to  the  assumption  of  so  many  distinct 
nerve  processes  and  sensations  is  that  it  gives  hearing 
a  disproportionate  number  of  qualities  when  compared 


VISION  87 

with  the  other  senses.  More  cogent  is  the  argument 
that  notes  an  octave  apart  seem  more  alike  than  notes 
within  the  octave.  Two  C's  are  more  likely  to  be  con- 
fused than  C  and  G,  or  C  and  B.  But  if  we  assume 
that  there  are  fewer  simple  primary  qualities  than  there 
are  distinguishable  tones,  there  is  as  yet  no  agreement 
as  to  what  these  primary  qualities  are,  or  how  many 
there  are  of  them. 

Visual  Sensations.  —  By  far  the  most  important  sense 
is  sight.  We  trust  vision  above  the  other  senses  in  per- 
ception, and  most  people  think  in  images.  When  we 
recall  an  object,  we  remember  how  it  looks  rather  than 
any  other  of  its  sensory  qualities.  In  discussing  sight 
we  have  again  to  consider  the  three  phases  of  the  visual 
process,  —  external  stimulus,  sense-organ,  and  sensa- 
tion. There  is  in  vision  rather  greater  dissimilarity  be- 
tween the  different  phases  than  in  hearing.  k  The  physical 
stimulus  is  a  vibration  in  the  hypothetical  ether.  The 
physicist  tells  us  that  the  ether  vibration  varies  in  the 
same  three  ways  as  the  sound  vibration.  Changes  in 
rate  or  in  length  of  the  wave  give  quality ;  changes  in  the 
amplitude  of  vibration  give  intensity ;  while  changes  in 
complexity  give  greys  and  colours  of  different  degrees 
of  saturation,  —  varying  mixtures  of  greys  with  colours. 
The  rate  or  length  corresponds  to  colour.  Red  has  a 
wave-length  of  some  800-833  n  n  (thousandths  of  thou- 
sandths of  a  millimetre),  violet  a  wave-length  of  less 
than  half,  or  380-400  ^  /*.  The  colours  between  have 
intermediate  wave-lengths.  Change  in  amplitude  pro- 
duces varying  brightnesses,  from  black  through  the  colours 
(what  colour  depends  upon  the  wave-length  of  the  light) 


88  THE  ESSENTIALS   OF  PSYCHOLOGY 

to  white.  Mixtures  of  certain  light-waves  give  white 
or  grey,  and  of  others  give  different  spectral  colours 
according  to  the  wave-lengths  that  are  mixed.  In  any 
case  it  is  evident  that  the  qualities  of  the  things  as  we 
see  them  are  not  at  all  like  the  vibrations  which  cause 
them.  There  is  nothing  in  the  colours  to  indicate  that 
violet  is  a  more  rapid  vibration  than  red.  There  are 
many  disparities  even  in  relations.  Red  and  violet 
are  more  unlike  physically,  but  the  sensations  are  more 
alike  than  those  of  red  and  yellow,  or  of  red  and  any 
intermediate  colour  nearer  red  in  vibration  rate. 

The  Structure  of  the  Eye.  —  The  key  to  the  difference 
between  the  physical  stimulus  and  the  qualities  of  colour 
must  lie  in  the  eye.  That  vibrations  of  different  lengths 
give  similar  sensations  must  be  due  to  the  similarity  of 
the  physiological  processes  which  they  arouse  in  the 
retina.  The  eye  can  be  best  understood  if  it  is  compared 
to  a  camera.  Three  parts  are  essential  to  a  camera: 
the  box  or  container,  the  lens,  and  the  sensitive  plate. 
The  box  or  frame  of  the  eye  is  to  be  found  in  the  sclerotic 
coat,  the  tough  membrane  that  holds  the  parts  together, 
and  is  kept  distended  into  a  sphere  by  the  pressure  of 
the  liquid  within.  The  organ  is  mounted  in  its  socket, 
a  conical  hollow  in  the  skull.  It  is  held  in  its  socket  by 
threads  of  connective  tissue  and  is  turned  by  three  pairs 
of  muscles.  Within  the  sclerotic  coat  is  first  the  choroid 
coat  which  nourishes  the  eye  and  has  some  nerves  and 
muscular  fibres ;  within  that  is  the  retina  which  cor- 
responds to  the  sensitive  plate.  The  lens  system  of  the 
eye  is  made  up  of  two  parts,  the  cornea  and  the  crystal- 
line lens.  The  cornea  is  really  only  a  part  of  the  sclerotic 


THE  EYE 


r      w 


89 


FIG.  19.  — Section  of  eye.  (Scler.)  sclerotic  coat;  (Chor.)  choroid;  (Ret.) 
retina;  (Opt.)  optic  nerve;  (Fov.  c.)  fovea;  (Pr.  cil.)  ciliary  process,  under  it 
is  the  ciliary  muscle  which  adjusts  the  lens  for  different  distances;  (Conj.) 
conjunctiva.  (Cam.  ant.)  is  the  anterior  chamber,  filled  with  the  aqueous 
humour ;  (Corpus  vitreum)  is  the  vitreous  humour  that  fills  the  main  body  of 
the  eye.  (From  Angell's  'Psychology,'  Fig.  47.) 

coat  which  projects  slightly  and  forms  in  consequence  a 
stronger  lens.  It  is  transparent  instead  of  white  and 
opaque  as  is  the  sclerotic  coat.  The  lens  is  just  back  of 


90          THE  ESSENTIALS  OF  PSYCHOLOGY 

the  iris,  the  membrane  which  by  its  pigment  gives  the 
characteristic  colour  to  the  eye.  It  is  attached  to  the 
choroid  coat  by  a  ligament,  the  suspensory  ligament. 
That  in  turn  is  connected  with  the  ciliary  muscle  which 
forms  part  of  the  choroid  coat.  In  front  of  the  lens  lies 
the  anterior  chamber  filled  with  a  liquid  much  like  water, 
as  its  name,  aqueous  humour,  implies.  Back  of  the  lens 
is  a  large  chamber,  filled  with  the  jellylike  vitreous 
humour. 

The  Eye  as  an  Optical  Instrument.  —  The  rays  of  light 
are  bent  at  the  front  surface  of  the  cornea,  and  at  the 
two  surfaces  of  the  lens.  The  whole  system  has  the 
same  effect  as  if  the  light  came  through  a  single  pinhole 
15  mm.  in  front  of  the  retina  or  7  mm.  back  of  the 
cornea.  The  size  of  the  image  of  any  object  thrown 
upon  the  retina  will  be  found  by  drawing  a  line  from 
the  sides  of  the  object  to  the  retina  through  this  nodal 
point  where  the  pinhole  might  be.  One  extremely  im- 
portant function  of  the  lens  is  the  accommodation  or 
focussing  of  the  eye.  A  camera  that  cannot  be  adjusted 
for  different  distances  is  of  little  value  since  pictures 
could  be  taken  at  one  distance  only.  An  eye  with  a 
fixed  system  of  lenses  could  see  objects  at  but  one  dis- 
tance. The  eye  is  accommodated  for  different  distances 
by  changing  the  shape  of  the  lens.  The  lens  is  relatively 
flat  when  one  is  looking  at  a  distant  object,  but  becomes 
thick  and  well  rounded  when  one  looks  at  a  near  object. 
This  thickening  of  the  lens  may  be  seen  if  one  will  look 
across  another's  eye  as  he  looks  at  objects  at  different 
distances.  When  the  eye  is  adjusted  for  distance,  the 
iris  is  flat;  when  it  is  focussed  on  a  finger  held  close, 


THE   EYE  QI 

the  iris  is  pushed  forward  by  the  lens.  The  shape  of 
the  lens  is  changed  by  the  contraction  of  the  ciliary 
muscle.  When  looking  at  a  near  object  the  muscle 
contracts  and  permits  the  lens  to  take  on  its  normal, 
rather  round  shape.  When  the  muscle  is  relaxed,  the 
lens  is  tightly  stretched  by  the  suspensory  ligament 
and  so  becomes  flatter  and  thinner.  (See  diagram.) 
Another  adjustment  of  the  eye  that  may  be  mentioned 
is  the  change  in  the  size  of  the  pupil.  The  iris  is  really 
a  part  of  the  choroid  coat  that  might  have  been  drawn 
away  from  the  attachment  to  the  cornea.  The  pupil  is 
the  hole  in  the  iris.  When  the  eye  is  in  the  dark,  the 
muscles  that  hold  the  pupil  open  are  contracted ;  when 
the  light  is  bright,  the  sphincter  of  the  iris  contracts, 
the  other  muscles  relax,  and  the  pupil  becomes  small. 
The  dilation  permits  a  larger  amount  of  light  to  enter 
the  eye,  the  contraction  protects  the  eye  against  too 
bright  light. 

The  real  seeing  portion  of  the  eye  is  the  retina.  The 
retina  is  a  part  of  the  brain  that  has  come  to  the  surface 
in  the  course  of  development.  It  is  made  up  of  three 
layers  of  neurones.  The  structures  that  receive  the 
light  are  the  rods  and  cones.  These  are  farthest  away 
from  the  light,  nearest  the  .choroid  coat.  There  is  an 
intermediate  and  an  inner  neurone  layer.  The  axones 
of  the  inner  layer  of  so-called  large  ganglion  cells  com- 
bine to  form  the  optic  nerve.  In  exciting  the  eye  a  ray 
of  light  traverses  the  outer  neurones  as  a  physical  im- 
pulse (vibration  in  the  ether),  strikes  upon  the  rods  and 
cones,  is  there  transformed  into  a  nervous  impulse  and 
transferred,  first  to  the  intermediate  bipolar  cells,  then 


THE  ESSENTIALS   OF  PSYCHOLOGY 


FIG.  20.  —  Schematic  diagram  of  the  nervous  structure  of  the  retina.  (/)  the 
layer  of  pigment  cells ;  (//)  the  rods  and  cones ;  (VI)  the  bipolar  cells;  (IX) 
the  large  ganglion  cells ;  and  (X)  the  axones  that  later  unite  to  constitute  the 
optic  nerve.  (From  Professor  Calkins,  Fig.  14,  after  Howell.) 


THE   EYE  93 

to  the  outermost  large  ganglion  cells,  and  finally  is 
carried  back  to  the  brain.  Thus  the  nervous  impulse 
goes  back  over  part  of  the  course  that  was  traversed 
originally  by  the  light-wave. 

Fovea  and  Blind  Spot.  —  At  the  centre  of  the  retina 
is  a  small  depression  or  pit  known  as  the  fovea.  In  and 
about  this  the  retina  has  a  yellow  pigment  which  gives 
the  name,  yellow  spot,  to  the  general  region.  Owing 
to  the  pit  the  light  suffers  less  absorption  than  at  other 
portions  of  the  retina  in  reaching  the  sensitive  struc- 
tures. In  the  fovea  there  are  only  cones,  and  they  are 
more  closely  set  than  elsewhere.  The  lack  of  absorp- 
tion and  the  slight  distance  that  separates  the  cones 
make  the  fovea  the  point  of  clearest  vision.  From  the 
fovea  outward  the  cones  decrease  in  number  until  on 
the  periphery  they  practically  disappear.  The  en- 
trance of  the  optic  nerve  is  not  provided  with  rods  and 
cones  and  in  consequence  is  not  sensitive  to  light.  It 
is  what  is  known  as  the  blind  spot.  We  know,  then, 
that  the  vibrations  in  the  ether  come  to  the  rods  and 
cones  in  the  deepest  coat  of  the  retina.  There  in  some 
way  they  are  transformed  into  nerve  impulses,  pass 
from  one  to  another  of  the  three  neurones  in  the  eye, 
and  then  to  the  basal  ganglia  and  cortex. 

Vision  a  Photo-chemical  Process.  —  The  first  ques- 
tion of  function  is  how  ether  vibrations  are  changed  to 
nerve  impulses.  An  analogy  for  this  is  found  in  the 
action  of  light  in  producing  chemical  changes  in  the 
photographic  plate.  It  is  possible  to  observe  directly 
changes  of  this  kind  in  the  visual  purple  found  in  the 
outer  portions  of  the  rods.  This  bleaches  when  exposed 


94  THE   ESSENTIALS    OF   PSYCHOLOGY 

to  light  and  becomes  purple  when  the  eye  is  kept  in  the 
dark.  The  bleaching  of  the  visual  purple  has,  however, 
only  an  indirect  relation  to  seeing.  The  increased  sensi- 
tiveness that  comes  after  a  long  period  in  the  dark  is 
due  to  the  effect  of  the  visual  purple,  but  ordinary  day- 
light vision  is  practically  unaffected  by  it. 

Primary  Colours  and  Their  Combinations.  —  For  an 
explanation  of  the  action  of  the  retina  we  are  compelled 
to  rely  upon  indirect  evidence  obtained  by  experiment 
and  observation.  We  may  be  guided  again  by  the  doc- 
trine of  specific  energies.  There  are  apparently  six 
specific  qualities  from  which  all  visual  processes  must  be 
derived.  These  are  the  two  brightnesses,  white  and 
black,  and  four  colours,  red,  yellow,  green,  and  blue. 
The  spectral  qualities  and  purple  are  obtained  from  the 
four  primary  colours.  Orange  is  a  combination  of  red 
and  yellow  and  may  be  produced  by  combining  red  and 
yellow  lights  in  the  right  proportions.  When  a  spec- 
trally pure  ray  of  orange  light  falls  upon  the  retina,  it 
excites  the  two  responses  red  and  yellow  in  different 
degrees,  and  the  results  of  the  two  physiological  pro- 
cesses combine  in  the  brain  or  in  consciousness  to  pro- 
duce the  single  sensation  of  orange.  Similarly,  yellow 
and  green  combine  to  produce  canary  yellow,  green 
and  blue  to  give  robin's  egg  blue  and  other  shades. 
Finally  the  circle  is  completed  by  the  fact  that  red 
combines  with  blue  to  give  first  indigo,  then  violet 
and  the  whole  series  of  purples  that  fill  the  gap  be- 
tween the  ends  of  the  spectrum.  It  is  interesting  to 
note  that,  while  all  the  other  mixed  colours  may  be 
produced  either  by  having  a  single  pure  light-wave  fall 


SENSATIONS   OF    SIGHT 


95 


upon  the  retina  or  by  combining  two  lights  in  proper 
proportions,  the  purples  can  be  induced  only  by  com- 
bining -lights.  There  is  no  single  ether-wave  that  gives 
a  purple  colour.  Nevertheless,  purple  is  quite  as  uni- 
tary in  sensation  as  any  of 
the  colours  due  to  a  single 
wave-length. 

The  relation  of  the  spectral 
colours  to  the  simple  colours 
may  be  illustrated  by  a  square. 
(See  diagram,  Fig.  21.)  The 
corners  represent  the  simple 
colours,  the  sides  the  combina- 
tions that  may  be  produced 
from  them.  With  each  of  these 
colours  a  brightness  is  com- 
bined. These  series  of  bright- 
nesses extend  from  black  to 
white.  All  wave-lengths  excite 
the  brightnesses,  and  the  qual- 
ity of  the  brightness  depends 

.  ,.,  PI 

upon  the  amplitude  of  the 
wave,  not  at  all  upon  the 
length.  Each  of  the  waves  at  a  certain  moderate 
intensity  excites  brightness  in  very  slight  degree,  colour 
in  larger  amount.  This  is  the  pure  spectral  colour. 
A  faint  red  light  appears  black  because  it  affects  the 
brightness  organ  only  ;  as  it  grows  brighter  it  becomes 
first  dark  brown,  then  dark  red,  then  red,  then  bright 
red  and  pink,  and  with  very  great  intensities  approaches 
white.  Where  the  colour  is  present  in  greatest  proper- 


FlG-    "•  ~  Colour    pyramid- 

(From  Titchener:    'Textbook 

o{  Psychology>,  Fig.  IS-) 


96  THE  ESSENTIALS   OF   PSYCHOLOGY 

tion,  it  is  said  to  be  saturated.  As  the  grey  becomes 
more  and  more  prominent,  the  colour  is  said  to  be  less 
and  less  saturated.  These  degrees  of  saturation  are 
represented  by  the  radiating  lines  on  the  square  of  the 
colour  pyramid. 

Complementary  Colours.  —  One  result  of  mixing 
colours,  the  phenomenon  of  complementary  colours, 
is  particularly  important  for  theory.  When  colours  at 
opposite  corners  of  our  colour  square  are  mixed  in 
suitable  proportions,  they  give,  not  an  intermediate 
colour,  but  brightness.  Apparently  the  complementary 
colours  produce  exactly  opposite  effects  upon  the  sub- 
stance sensitive  to  them:  each  destroys  the  effect  of 
the  other.  When  they  thus  neutralise  each  other,  the 
only  effect  is  to  excite  the  organ  of  brightness,  and  the 
result  is  white,  grey,  or  black,  according  to  the  intensity 
of  the  colours.  When  any  two  colours  are  mixed,  there 
is  always  partial  cancellation,  and  the  resulting  colours 
are  always  less  saturated  than  the  components  would  be. 
If  all  the  colours  of  the  sun's  rays  are  mixed,  the  com- 
ponents all  cancel  each  other  and  the  result  is  the  white 
or  slightly  yellowish  daylight.  We  may  represent  the 
greys  upon  our  diagram  by  a  line  BW  through  the  centre 
of  the  square  extending  above  and  below.  The  fact 
that  each  light  ray  at  a  slight  intensity  excites  only 
grey  or  black  may  be  indicated  by  connecting  each  corner 
of  the  square  with  the  ends  of  the  line.  It  seems  prob- 
able, too,  that  the  lights  in  maximum  intensity  excite 
only  the  brightness  organ.  This  is  represented  by  con- 
necting each  corner  of  the  square  with  the  top  of  the 
brightness  line  as  well.  Thus  drawn,  every  point  on 


SENSATIONS   OF    SIGHT  97 

the  pyramid  inside  and  out  represents  some  colour  or 
shade,  and  all  visual  qualities  are  represented. 

After-images.  —  The  fact  of  complementariness  makes 
it  probable  that  the  colour  qualities  of  each  pair  have 
their  seat  in  a  single  organ.  This  assumption  is  fur- 
thered by  other  facts  of  vision.  Thus  if  one  looks  at 
any  colour  or  any  brightness  for  a  few  seconds  and  then 
looks  at  another  surface,  the  complementary  colour  will 
be  seen.  Red  gives  an  after-image  of  green,  yellow  an 
after-image  of  blue,  and  vice  versa.  It  is  assumed  that 
the  after-image  is  due  to  the  fact  that  when  the  organ 
is  excited  in  one  way,  recovery  from  the  excitation  gives 
the  complementary  colour. 

Colour-Blindness.  —  Even  stronger  evidence  for  as- 
signing each  pair  to  a  single  organ  is  derived  from  the 
phenomenon  of  colour-blindness  and  the  distribution  of 
the  colours  upon  the  retina.  Individuals  are  found  who 
lack  altogether  the  red  and  green  components  of  colour, 
but  none  who  can  be  shown  to  be  altogether  lacking  in 
one  alone.  If  one  is  colour-blind,  it  is  either  to  red  and 
to  green  or  to  all  colours,  never  to  red  or  to  green  alone. 
Approximately  three  per  cent  of  the  male  population 
is  colour-blind  in  sufficient  degree  to  be  uncertain  in  the 
discrimination  of  red  from  green.  Since  for  some  reason 
the  railway  and  navigation  authorities  hit  upon  these 
two  colours  for  their  signals,  it  is  essential  that  all 
colour-blind  men  be  excluded  from  their  employ,  hence 
the  careful  examination  to  which  they  subject  applicants 
for  work.  The  phenomena  of  colour-blindness  are  pres- 
ent in  every  normal  eye.  In  a  band  about  the  centre 
red  and  green  cannot  be  seen.  Beyond  this  band  the 

H 


98         THE  ESSENTIALS  OF  PSYCHOLOGY 

eye  is  totally  colour-blind;  only  black  and  white  are 
appreciated  there.  This  outer  colour-blindness  may 
be  demonstrated  by  moving  a  small  bit  of  paper  of  some 
colour  out  toward  the  periphery  of  the  field  of  vision 
while  the  eye  is  kept  fixed  upon  a  point.  If  the  colour 
be  primary,  it  will  turn  to  grey  when  it  changes  at  all 
in  quality.  If  it  be  a  composite  colour  like  orange,  it 
will  change  first  to  yellow  and  then,  when  it  gets  beyond 
the  blue-yellow  zone,  to  grey. 

The  Colour  Pairs  Seen  with  a  Single  Organ.  —  These 
phenomena  taken  together  indicate  that  colour  qualities 
are  connected  in  pairs  with  their  organs.  Red  and  green 
have  a  single  organ  as  have  blue  and  yellow,  black  and 
white.  The  process  that  gives  red  is  in  some  way  op- 
posed to  the  process  that  gives  green.  Yellow  is  opposed 
to  blue  in  the  same  way.  There  is  less  evidence  that 
black  and  white  are  opposed,  but  that  is  still  the  usual 
assumption.  When  opposed  processes  are  excited,  they 
destroy  each  other ;  when  one  is  excited  and  the  stimulus 
withdrawn,  the  other  colour  makes  its  appearance. 
When  one  colour  disappears  or  is  not  found,  the  other 
also  is  not  present.  No  altogether  satisfactory  explana- 
tion of  what  the  change  is,  or  of  what  the  nature  of  the 
opposition  may  be,  has  been  found,  but  that  the  process 
is  a  chemical  one,  and  that  the  two  directions  are  op- 
posed is  generally  accepted. 

Colour  Contrast.  —  One  other  phenomenon  related 
to  complementariness  and  after-images  is  contrast.  If 
two  complementary  colours  are  placed  side  by  side,  each 
becomes  brighter  because  of  the  presence  of  the  other. 
If  a  colour  is  seen  against  a  grey  background,  it  will  be 


SENSATIONS   OF    SIGHT  9Q> 

surrounded  by  a  fringe  of  the  complementary  colour. 
Red  will  give  a  green,  blue  a  yellow,  and  so  on.  The- 
contrast  effect  may  be  observed  if  a  small  patch  of  grey 
paper  be  placed  upon  a  coloured  surface.  The  effect 
will  be  increased  if  a  bit  of  translucent  paper  be  put  over- 
the  colour  and  the  square  of  grey.  Contrast  colours 
are  also  very  clearly  seen  when  a  shadow  is  thrown 
upon  a  coloured  field,  as  when  two  shadows  of  the  same 
object  are  cast  by  different  coloured  lights.  The  ex- 
planation of  contrast  is  probably  to  be  found  in  the 
opposition  between  the  chemical  processes  excited  by 
complementary  colours.  When  a  surface  is  stimulated 
by  one  light,  the  opposite  process  is  induced  in  the 
surrounding  areas  of  the  retina. 

The  Colourless  Visual  Sensations. — Whenever  light 
which  does  not  affect  the  colour  processes  stimulates 
the  retina,  brightness  or  black-white  sensations  result. 
All  light  affects  the  black- white  organ,  but  when  the 
colour  processes  are  also  stimulated  they  are  appreciated 
only  as  they  make  the  colour  brighter  or  darker  or  re- 
duce its  saturation.  Brightness  alone  is  appreciated, 
as  has  been  seen,  when  complementary  colours  cancel 
each  other ;  in  the  eyes  of  the  totally  colour-blind  and 
on  the  periphery  of  the  normal  eye ;  when  the  lights  are 
too  faint  to  excite  the  colour  processes ;  and  when  the 
coloured  objects  are  very  small  or  the  stimulus  has  a 
very  short  duration.  In  the  dark  all  colours  become 
greys  of  different  shades.  Very  small  patches  of  colour 
are  also  grey.  A  coloured  object  at  a  great  distance 
becomes  a  grey  of  a  brightness  that  corresponds  to  the; 
intensity  of  the  light.  It  is  for  this  reason  that  very 


TOO  THE   ESSENTIALS    OF   PSYCHOLOGY 

brilliant  colours  may  be  used  in  the  uniforms  of  troops. 
When  seen  from  a  distance  these  stimulate  a  very  small 
patch  on  the  retina,  and  if  they  are  of  the  brightness  of 
the  surrounding  natural  objects  will  not  be  observed. 
The  light  blue  of  the  French  uniforms,  the  khaki  of  the 
British  and  American  troops,  and  the  light  grey  of  the 
German  are  equally  difficult  to  detect  at  a  distance. 
When  different  colours  of  slight  extent  are  interspersed 
or  larger  patches  side  by  side  are  seen  from  a  great 
distance,  they  combine  just  as  they  do  when  mixed  by 
rotation.  Thus  the  small  bits  in  a  mosaic,  or  the  differ- 
ent coloured  threads  in  worsted  combine  to  produce 
uniform  shades. 

At  present  all  agree  that  there  are  two  organs  for 
brightness,  one  for  faint  and  another  for  bright  or 
moderate  lights.  The  faint  lights  affect  the  rods  alone, 
and  the  brighter  lights,  the  cones.  The  light  that  is 
noticed  at  night  after  one  has  been  long  in  the  open 
excites  the  rods.  The  greater  sensitiveness  of  the  eye 
after  long  adaptation  to  the  dark  comes  from  the  in- 
crease in  the  amount  of  visual  purple  which  sensitises 
the  rods,  as  sensitive  plates  may  be  increased  in  sensi- 
tiveness by  the  application  of  proper  chemicals. 

Summary  of  the  Facts  of  Vision.  —  In  brief  we  may 
assume  that  there  are  six  processes  in  the  retina  from 
which  all  of  the  visual  qualities  are  compounded.  These 
six  qualities  are  grouped  in  pairs,  red  and  green,  blue  and 
yellow,  and  black  and  white,  and  each  pair  finds  physio- 
logical explanation  in  opposed  processes  in  the  same 
substance.  When  the  two  processes  are  equally  ex- 
cited simultaneously,  there  is  no  effect  upon  the  colour 


SENSATIONS   OF   MOVEMENT  IOI 

organ,  but  only  the  resulting  effect  upon  the  brightness 
organ.  When  one  process  has  been  aroused,  its  opposite 
succeeds  it  after  a  brief  persistence  of  the  first.  In 
colour-blindness  the  red-green  organ  is  most  often  lack- 
ing. Next  most  frequently  wanting  is  the  yellow-blue 
organ,  while  the  black- white  organ  is  always  present 
unless  the  eye  be  totally  blind.  It  is  interesting  to 
note  that  the  manifold  wave-lengths  in  ether  affect  the 
retina  in  but  six  different  ways.  However,  what  is 
lost  in  complexity  in  the  retina  is  got  back  with  interest 
in  consciousness.  The  six  processes  by  their  combina- 
tions give  rise  to  from  thirty  to  fifty  thousand  distin- 
guishable qualities.  It  is  interesting  to  note  that  the 
physiologically  complex  colours  are  little  if  any  less 
simple  as  conscious  qualities  than  the  simple  physio- 
logical colours.  So  true  is  this  that  just  what  are  the 
simple  physiological  qualities  is  still  a  matter  of  dispute. 
Each  colour  theory  has  a  different  set  of  primary  colours 
and  the  only  hope  of  agreement  depends,  not  upon  intro- 
spective analysis,  but  upon  physiological  experiment. 

Kinaesthetic  Sensations.  —  In  addition  to  the  tradi- 
tional five  senses  of  man,  many  new  sense  qualities  and 
sense-organs  have  been  discovered  relatively  recently. 
Most  important  of  these  is  the  sensation  complex  that 
tells  us  of  the  movement  of  the  body,  of  weight,  and  re- 
sistance. When  one  moves  the  hand,  one  knows  at 
once  the  amount  and  direction  of  the  movement  even 
with  the  eyes  closed.  Pathological  cases  are  found, 
however,  in  which  the  patient  is  unconscious  of  move- 
ment and  of  weight.  When  he  moves,  he  has  no  idea 
that  he  has  moved,  and  he  has  no  idea  of  the  position 


102        THE  ESSENTIALS  OF  PSYCHOLOGY 

of  his  members  when  they  are  at  rest.  These  cases 
emphasise  the  fact  that  the  normal  man  must  have 
some  special  sense-organ  for  the  detection  of  move- 
ments. Investigation  has  shown  that  the  sensations 
come  from  organs  in  the  muscles  and  tendons.  In  the 
tissue  of  muscles  and  tendons  are  sense-organs  not  unlike 
some  of  the  organs  found  in  the  skin.  When  the  muscle 
is  contracted,  the  cells  of  the  muscle  become  shorter  and 
thicker.  This  change  exerts  pressure  upon  and  stimu- 
lates the  sensory  ends  between  the  muscle  cells.  For 
example,  whenever  the  arm  is  moved,  there  is  a  con- 
traction in  one  set  of  muscles  and  a  relaxation  in  the 
opposing  set.  In  one  set  of  muscles  the  sense-organs 
will  be  compressed,  in  the  other  set  the  pressure  will 
be  relaxed.  Each  movement  and  each  position  has  a 
complex  of  increasing  and  decreasing  stimulations  which 
is  characteristic  for  that  movement  in  quality  and  in- 
tensity. Strains  and  weights  when  the  arm  is  not 
moved  reveal  themselves  in  similar  pressure  exerted 
upon  the  sense-organs  of  the  tendons  in  addition  to 
that  upon  the  muscle-organs.  It  is  by  these  organs  that 
we  become  aware  of  the  fundamental  physical  properties 
of  the  world,  —  of  motion,  of  energy,  and  of  mass. 

The  Static  Sense.  —  One  of  the  most  interesting  of  the 
recently  discovered  sense-organs  is  the  organ  of  the 
static  sense  found  in  the  semicircular  canals  and  neigh- 
bouring organs  of  the  ear.  Hairs  project  into  the  liquid 
of  the  semicircular  canals.  When  the  liquid  is  disturbed 
by  the  motion  of  the  body,  the  hairs  are  moved  and  they 
in  turn  excite  the  nerves  connected  with  them.  These 
impulses  are  transmitted  to  the  motor  neurones  that 


THE   STATIC   SENSE  103 

control  the  movement  of  the  body,  and  movements  are 
made  which  adjust  the  members  to  the  new  position  or 
bring  the  body  back  to  the  upright.  When  the  organs 
of  the  labyrinth  are  injured,  proper  motor  adjustments 
are  difficult  or  impossible.  An  animal  with  injured  semi- 
circular canals  will  not  be  able  to  stand,  or  at  least  to 
stand  steady.  When  the  organs  are  lacking  in  man, 
reflex  eye-movements  are  wanting.  It  is,  perhaps,  a 
question  whether  the  static  sense  is  a  real  sense,  for  we 
become  aware  of  its  action  only  indirectly  through  the 
movements  it  induces  or,  when  the  excitation  is  more 
intense,  by  the  disturbances  of  the  alimentary  tract  that 
give  rise  to  the  sensation  of  giddiness.  When  still  more 
intense,  the  stimuli  from  these  organs  call  out  the 
more  active  phenomenon  of  vomiting  involved  in  sea- 
sickness. What  the  immediate  quality  of  the  sensation 
from  the  static  sense  may  be,  is  not  known. 

Organic  Sensations.  —  Many  other  sense-organs  and 
sense  qualities  are  known  less  definitely.  The  sensations 
from  them  have  not  been  satisfactorily  analysed,  and 
their  organs  are  not  well  known  from  physiological  ex- 
periments. We  ordinarily  group  them  into  a  single 
mass  of  organic  sensation.  Of  these  hunger  has  been 
shown  recently  to  be  due  to  the  reflex  contraction  of 
the  walls  of  the  stomach.  Thirst  has  its  seat  in  the 
upper  throat  or  back  of  the  mouth.  It  is  probable  that 
there  are  special  organs  that  inform  us  of  circulatory 
disturbances,  of  the  respiratory  processes,  and  of  many 
others  less  well  distinguished.  One  is  aware  of  feeling 
well  or  feeling  ill,  and  if  one  will  examine  the  experience 
more  closely,  vague  sensory  qualities  may  be  analysed 


104  TSE'  ESSENTIALS   OF  PSYCHOLOGY 

from  the  mass.  It  is  to  be  hoped  that  these  complexes 
of  organic  sensation  may  some  day  be  analysed  and 
their  sense-organs  determined.  Until  that  time  we  can 
merely  refer  to  the  mass  and  say  nothing  more. 

Summary  of  Sense  Qualities.  —  If  we  sum  up  the  re- 
sults of  this  discussion  of  the  qualities  of  sensation,  we 
find  that  there  are  relatively  few  simple  qualities  re- 
ceived from  sense-organs  and,  regarded  from  the  physio- 
logical side,  relatively  few  sorts  of  sense  endings.  A 
table  will  show  the  number  of  qualities  from  each  sense. 

Qualities  from  the  skin 4 

Qualities  of  taste 4 

Qualities  of  smell uncertain  (9?) 

Qualities  of  hearing uncertain  (11,000?) 

Qualities  of  sight       6 

Qualities  of  kinaesthetic  sensations  .     .     .     .  i  or  2 

Qualities  of  organic  sensations ioori2(?) 

In  all  there  are  but  forty  or  fifty  different  sorts  of  nerve 
ends  from  which  all  the  varieties  of  our  conscious  qualities 
are  derived.  We  might  obtain  a  much  larger  total  if  we 
considered  the  number  of  qualities  that  could  be  recog- 
nised by  unaided  observation  as  distinct  in  consciousness. 
Then  we  should  have  11,000  tones,  some  40,000  colour 
qualities,  unlimited  tactual  qualities,  the  different  com- 
plexes of  taste  and  smell,  one  for  each  distinguishable 
substance,  —  to  say  nothing  of  the  vast  number  of 
organic  complexes  that  change  with  each  of  our  moods, 
and  with  our  condition  of  health.  Enumeration  on  this 
basis  has  never  been  attempted  except  for  sight  and 
sound,  but  it  is  probable  that  the  other  senses  give  similar 
large  numbers  of  sensations  or  complexes  of  sensations. 


WEBER  S   LAW  10$ 

Intensities  of  Sensation.  —  One  other  aspect  or  attri- 
bute of  sensation  important  in  practice  is  intensity.  The 
intensity  of  sensation  is  dependent  upon  the  intensity 
of  the  stimulus.  The  more  energy  acts  upon  the  sense- 
organ,  the  greater  the  intensity.  While  intensities  play 
a  very  large  part  in  our  life,  they  are  not  easily  described 
or  even  thought  of  in  absolute  terms.  They  cannot  be 
easily  remembered.  We  have  no  accurate  names  for 
the  degrees  of  intensity  in  our  non-scientific  vocabulary. 
Pounds  and  kilograms,  ergs  and  horse-power,  are  ob- 
viously artificial  units  and  correspond  to  nothing  that 
we  can  picture  easily.  For  everyday  usage  slight, 
moderate,  and  intense  are  the  only  terms  available  to 
designate  intensities.  The  difficulty  in  description  and 
discussion  is  all  the  more  marked  because  experiments 
show  that  there  is  no  direct  relation  between  the  in- 
tensity of  the  physical  stimulus  and  the  resulting  con- 
sciousness. As  nearly  as  one  can  make  out  a  thousand 
ounces  do  not  give  a  thousand  times  as  much  weight 
sensation  as  one  ounce.  Sensations  seem  to  increase  in 
amount  very  much  more  slowly  than  stimuli  increase  in 
intensity,  —  if  one  may  speak  of  the  amount  of  sensation 
at  all.  Intensities  of  sensation  cannot  be  described  by 
words  as  we  describe  qualities  of  sensation,  and  they  can- 
not be  measured  by  measuring  the  in  tensity  of  the  physical 
stimulus  and  assuming  that  the  sensation  will  harmonise 
with  that.  Both  the  simple  methods  of  approach  fail  us. 

Weber's  Law.  —  The  attempt  to  discover  some  means 
of  dealing  with  the  intensities  of  sensation  led  indirectly 
to  the  establishment  of  a  law  of  relation  between  stimulus 
and  sensation  which  is  known  from  the  name  of  the  man 


106        THE  ESSENTIALS  OF  PSYCHOLOGY 

who  first  noticed  the  relation  as  Weber's  law.  This 
asserts  that  the  least  noticeable  difference  between  two 
stimuli  is  not  constant  for  all  intensities,  but  varies 
with  the  intensity  of  the  stimuli  compared.  Thus  in 
lifting  weights  one  can  distinguish  between  an  ounce 
and  an  ounce  and  a  fortieth.  But  if  a  pound  be  the 
standard,  one  cannot  notice  the  addition  of  a  fortieth 
of  an  ounce ;  a  fortieth  of  a  pound  must  be  added.  In 
any  sense-department  it  has  been  found  that  an  addi- 
tion to  be  just  noticed  must  be  some  fraction  of  the 
stimulus  present,  rather  than  an  absolute  amount.  The 
fraction  that  must  be  added  is  different  for  each  sense. 
It  varies  from  about  one  one-hundredth  for  sight  to  about 
one-third  or  one-fourth  for  smell.  Several  different 
formulae  have  been  used  to  express  the  relation.  Per- 
haps the  best  known  and  the  simplest  is  that  sensations 
increase  in  arithmetical  ratio,  as  stimuli  increase  in  geo- 
metrical ratio.  The  stimulus  must  always  be  multiplied 
by  some  fraction,  —  for  passive  pressure,  e.g.  by  four- 
thirds  (|)  to  obtain  the  next  unit  of  sensation. 

Deviations  from  Weber's  Law.  —  The  most  obvious 
outcome  of  the  law  in  everyday  life  is  that  only  relative 
differences  can  be  appreciated.  One  is  aware  of  the 
relative  difference  in  brightness  between  the  black  of 
the  print  and  the  white  of  the  page,  but  is  not  aware 
of  the  absolute  change  in  the  brightness  of  each  between 
noon  and  evening.  Were  the  law  to  hold  absolutely, 
the  light  might  fade  and  we  be  unaware  of  it.  The 
fraction  that  can  be  noticed  is  not  absolutely  constant, 
however,  but  holds  only  for  the  middle  ranges  of  in- 
tensity. As  the  light  grows  dim,  the  just  distinguishable 


WEBER'S  LAW  107 

differences  must  increase,  until  at  twilight  white  must 
be  more  than  sixty  times  as  bright  as  the  black  of  the 
print  to  be  readily  noticed  as  different  from  it.  Simi- 
larly, as  the  absolute  brightness  is  increased,  the  frac- 
tion increases  or,  put  the  other  way,  the  relative  sensi- 
tivity decreases.  Slight  differences  are  not  so  easily 
noticed  in  the  full  glare  of  the  sun  as  in  diffuse  daylight. 
One  cannot  read  ordinary  print  at  night  or  with  ease 
in  the  glare  of  the  noonday  sun. 

The  Sensation  Threshold.  —  Not  only  may  differences 
between  intensities  be  too  slight  to  be  noticed,  but  stimuli 
may  be  too  faint  to  give  rise  to  any  sensation  whatever. 
As  one  moves  a  watch  away  from  the  ear,  the  sound 
becomes  fainter  and  fainter  until  it  finally  disappears. 
One  may  touch  a  pressure  spot  on  the  skin  with  a  hair 
so  soft  that  it  gives  no  sensation.  The  intensity  that 
can  be  barely  noticed,  that  first  gives  rise  to  a  sensation, 
is  called  the  liminal  or  threshold  stimulus.  At  the  other 
extreme  it  is  probable  that  a  stimulus  may  be  too  in- 
tense to  be  felt.  Probably,  however,  intensities  that 
do  not  destroy  the  sense-organ  merely  tend  to  be  lost 
in  the  accompanying  pain ;  they  do  not  actually  dis- 
appear. The  upper  limen  is  of  relatively  little  im- 
portance, and  there  is  little  known  about  it  because  of  the 
injury  which  work  upon  it  might  do  to  the  sense-organ. 

QUESTIONS 

1.  \\hatisasensation?    Is  it  a  physiological  or  psychological 
process? 

2.  What   determines  the  quality  of  a  sensation?    Does  it 
depend  more  upon  the  stimulus  or  upon  the  organ  stimulated? 
Is  there  sound  when  there  is  no  ear  to  hear? 


108        THE  ESSENTIALS  OF  PSYCHOLOGY 

3.  What  is  the  physiological  zero  point?    Is  it  always  the 
same?    Is  it  the  same  for  the  exposed  hand  and  for  the  elbow 
which  has  just  been  uncovered  ? 

4.  What  elementary  sensations  are  excited  when  the  hand  is 
put  into  water  at  48°  C.?    at  10°  C.?    What  is  the  paradoxical 
cold  sensation? 

5.  Name  the  components  of  the  'taste'  of  ice  cream;  of  hot 
coffee ;  of  pepper. 

6.  Describe  the  action  of  the  three  small  bones  of  the  ear  during 
hearing. 

7.  Is  the  basilar  membrane  broader  near  the  oval  window  or 
near  the  apex  of  the  cochlea  ? 

8.  What  is  a  noise :    (a)  physically?   ffc)  physiologically? 

9.  What  is  an  octave  ?  an  overtone  ?  How  are  the  C  of  the  violin 
and  of  the  piano  different? 

10.  State  the  Helmholtz  theory  of  hearing.    What  facts  tend 
to  prove  it ;  what  to  disprove  it  ? 

11.  Are  the  ganglion  cells  or  the  rods  and  cones  nearer  the 
vitreous  humour  ?  nearer  the  pupil  ? 

12.  Why  is  vision  clearest  at  the  fovea? 

13.  Describe  the  different  forms  of  colour-blindness.    What 
sensation  does  the  colour-blind  man  receive  from  a  primary  red? 
from  orange? 

14.  Under  what  circumstances  does  the  normal  eye  see  grey? 
What  different  organs  are  excited  when  we  see  grey  ? 

15.  What  is  the  visual  purple?     Where  is  it  and  what  is  its 
function? 

16.  How  does  seeing  the  stars  at  night  and  not  during  the  day 
illustrate  Weber's  law  ? 

17.  What  is  meant  by  the  sensation  or  absolute  limen?   the 
difference  limen? 

EXERCISES 

i.  Mark  off  an  area  on  the  skin  a  centimetre  square.  Touch 
each  point  of  the  area  with  a  pointed  metal  rod  warmed  to  about 
40°  C.  Mark  the  spots  where  warmth  is  felt.  Repeat  with  the 


SENSATION  109 

rod  cooled  by  immersion  in  ice-water.  Mark  the  points  where 
cold  is  felt.  Compare  with  the  warm  spots.  Are  they  the  same  ? 
Stimulate  a  definite  cold  spot  with  a  rod  heated  to  about  55°  C. 
What  stimulus  do  you  receive ?  Why? 

2.  Press  gently  upon  the  different  regions  of  the  area  above  with 
a  pointed  toothpick  or  human  hair.     Mark  the  points  where  press- 
ure is  felt.     Go  over  the  same  area  with  a  sharpened  horsehair 
fastened  by  wax  to  a  handle.    Note  the  points  where  pain  is  felt. 
Compare  with  pressure  and  with  the  temperature  spots.     Can  you 
make  out  any  law  of  arrangement? 

3.  Observe  in  a  glass  the  red  openings  of  the  papillae  on  the  end 
of  the  tongue.     Mark  five  papillae  on  a  drawing  of  the  tongue. 
With  a  brush  stimulate  each  papilla  successively  with  a  solution  of 
salt,  sugar,  vinegar,  and  quinine.     Are  all  of  the  spots  sensitive 
to  each  substance?    How  can  you  explain  the  results  by  the 
doctrine  of  specific  energies? 

4.  Fatigue  the  nostril  for  camphor  by  smelling  a  lump  of  the 
gum  until  it  is  no  longer  perceived.     Try  the  nose  for  iodine. 
Fatigue  again  for  camphor  and  try  for  vanilla.     Test  in  the  same 
way  for  rubber,  asafcetida  and  other  substances.    What  do  the 
results  prove  of  the  nature  of  olfactory  qualities  ? 

5.  Draw  the  ear  to  demonstrate  the  relations  of  the  bones  of  the 
middle  ear  to  the  cochlea  and  the  auditory  nerve. 

6.  Demonstrate  the  presence  of  overtones  in  a  note  of  the  piano. 
Strike  the  lowest  C  while  the  key  that  gives  the  octave  is  held 
down.    As  the  first  key  is  dropped  you  will  hear  the  octave  still 
resounding  by  sympathetic  action  induced  by  the  first  overtone 
of  the  fundamental.    Proceed  in  the  same  way  to  determine  what 
other  overtones  are  present  in  the  note  first  struck.    How  do  these 
overtones  affect  the  ear? 

7.  Mix  blue  and  yellow  in  different  combinations  on  a  rotating 
colour-mixer.     If  this  be  not  at  hand,  a  substitute  may  be  prepared 
as  follows :   Place  a  square  of  yellow  paper  and  a  square  of  blue 
paper  of  the  same  size  a  foot  apart  upon  a  black  cloth  on  a  table. 
Hold  a  pane  of  clear  glass  vertical  midway  between  them  and  look 
through  the  glass  at  one,  and  adjust  the  second  square  so  that  its 


110        THE  ESSENTIALS  OF  PSYCHOLOGY 

reflected  image  covers  the  first.  When  the  two  colours  are  brought 
to  coincide  the  apparatus  makes  a  simple  colour  mixer.  The 
intensities  of  the  colours  may  be  varied  by  turning  the  glass  plate 
about  the  line  of  contact  with  the  table.  What  colour  does  the 
mixture  of  blue  and  yellow  give  rise  to  when  the  apparatus  is 
adjusted  to  give  equal  amounts  of  each?  Try  mixtures  of  other 
primary  colours  to  give  the  list  of  spectral  colours. 

8.  Place  a  bit  of  green  paper  over  a  dot  on  a  sheet  of  grey  paper. 
Look  intently  at  the  green  paper  for  ten  seconds.    Blow  the  green 
bit  away  and  look  for  three  seconds  or  so  at  the  dot.     What  colour 
replaces  the  green?    Repeat  with  the  other  colours  and  record 
results. 

9.  Place  a  centimetre  square  of  grey  paper  on  a  large  square  of 
red.     Cover  both  with  tissue  or  other  translucent  paper.    Note 
the  colour  of  the  small  square  as  seen  through  the  tissue  paper. 
What  gives  it  a  colour  ?    Test  on  surfaces  of  other  colours.    What 
is  the  general  law? 

10.  Look  steadily  at  a  point  on  a  wall,  preferably  a  grey  wall. 
Have  an  assistant  move  centimetre  squares  of  coloured  paper  away 
from  the  fixation  point.     Note  the  point  where  the  different  colours 
disappear  or  change.     Measure  the  distance  from  the  fixation  point 
in   different    directions.     Compare    the    distances    for   different 
colours.     Can  you  interpret  the  results  by  the  phenomena  of 
colour-blindness  mentioned  in  the  text  ? 

1 1 .  Draw  the  eye  showing  the  lens  system  and  its  relation  to  the 
iris,  retina,  and  various  coats.    On  a  larger  scale  draw  a  portion  of 
the  retina  that  shall  indicate  the  nervous  connections  between  the 
rods  and  cones  and  the  fibres  of  the  optic  nerve. 

12.  Bend  the  finger  at  the  second  joint.     Can  you  detect 
deeper  lying  sensations?     Can  you  distinguish  them  in  quality 
from  the  pressure  sensations?    What  is  the  sense-organ  that  gives 
rise  to  them? 

REFERENCES 

TITCHENER:  Textbook  of  Psychology,  pp.  59-224. 
ANGELL:  Psychology,  pp.  100-150. 


SENSATION  III 

Ho  WELL  :  Text-book  of  Physiology,  ch.  xviii. 

MYERS:  Experimental  Psychology,  vol.  I,  chs.  ii-ix. 

SEASHORE  :    Elementary  Experiments  in  Psychology,  chs.  i-iii, 

vii,  viii  (for  further  experiments  and  fuller  description  of  the 

experiments  described  in  the  exercises). 


CHAPTER  V 
SELECTION  AND  CONTROL— ATTENTION 

Omnipresence  of  Selection.  —  One  of  the  most  strik- 
ing facts  of  consciousness  is  selection  or  control.  A 
man  is  not  absolutely  under  the  domination  of  habit, 
of  external  stimulation,  or  of  the  habitual  elements 
in  the  thinking  processes,  but  can  decide  for  himself, 
within  limits,  what  he  shall  hear  or  see,  what  he  shall 
think  or  what  he  shall  do.  He  may  admit  faint  stimuli 
to  consciousness  while  stronger  ones  are  acting  upon  the 
sense-organs ;  he  may  repress  a  strong  habit  and  permit 
a  weaker  one  to  run  its  course;  or  he  may  choose  a 
faint  memory  when  several  that  are  ordinarily  more 
insistent  are  pressing  for  return.  Evidently,  selec- 
tion is  of  fundamental  importance  in  perception,  in 
action,  and  in  memory.  Since  selection  affects  so  many 
different  processes  and  has  so  many  different  phases, 
it  becomes  necessary  to  distinguish  between  the  ques- 
tions that  may  be  answered  in  the  same  way  everywhere 
and  those  that  must  be  treated  differently  in  each  field. 
Three  questions  must  be  answered  in  connection  with 
each  kind  of  selection :  (i)  what  is  the  effect  of  selec- 
tion upon  the  process  affected?  (2)  what  determines 
the  course  of  selection  ?  (3)  what  are  the  concomitants 
of  the  selective  activity?  Of  these  the  first  takes  differ- 
ent forms  in  each  field ;  the  second  and  third  are  geri- 


PHENOMENA   OF  ATTENTION  113 

eral :  an  answer  in  one  connection  will  hold  with  little 
change  for  both  of  the  others.  The  conditions  of  selec- 
tion and  the  means  of  knowing  that  selection  is  being 
made  are  the  same  for  perception,  for  memory,  and  for 
will.  In  this  chapter  we  shall  discuss  primarily  atten- 
tion or  the  selection  of  sensations  but  we  shall  also  point 
out  the  similarities  between  the  attention  processes 
and  the  control  processes  in  thought  and  action. 

Effects  of  Attention  on  Sensation.  —  The  general 
effects  of  selection  are  the  same  for  perception,  for 
thought,  and  for  action.  We  read  on  a  railroad  train 
in  spite  of  the  noise  and  other  distractions;  we  hear 
the  faint  sounds  of  a  conversation  in  a  storm  or  in  a  boiler 
shop  and  are  for  the  moment  not  aware  of  the  din.  When 
studying  attentively,  one  may  be  spoken  to  several  times 
without  being  disturbed.  Similarly,  one  can  continue 
a  train  of  thought  even  when  other  very  pleasant  mem- 
ories suggest  themselves  or  in  the  midst  of  external  dis- 
turbances. A  stimulus  that  has  given  rise  on  different 
occasions  to  a  number  of  different  responses  and  might 
now  be  the  means  of  exciting  several  different  movements 
will  arouse  but  one  of  these,  —  that  one  will  be  selected 
from  the  other  possible  ones.  Each  of  these  selections 
is  of  the  same  kind.  One  process  is  given  free  rein ;  all 
others  are  checked. 

More  frequently  in  attention,  the  processes  not  selected 
are  not  absolutely  excluded  from  consciousness,  but  are 
given  a  subordinate  place.  As  one  attends,  certain  sen- 
sations are  clearly  appreciated ;  the  others  are  less  clear. 
One  of  the  much  discussed  problems  of  attention  concerns 
the  difference  between  the  sensation  directly  attended 


114  THE   ESSENTIALS   OF   PSYCHOLOGY 

to  and  the  others  that  constitute  the  background  of 
consciousness.  Two  conflicting  theories  have  been  held : 
one,  that  attention  increases  the  intensity  of  the  sensa- 
tion, the  other,  that  the  change  is  peculiar  and  must 
be  given  a  different  name,  clearness.  All  agree  that  the 
effect  of  attention  is  similar  to  increased  intensity.  Both 
make  the  sensation  easier  to  describe,  make  all  judgments 
about  it  more  accurate,  and  give  it  a  more  important 
place  in  consciousness.  But  the  two  effects  must  be 
different  in  some  way  for  one  seldom  mistakes  a  change 
in  attention  for  a  change  in  the  intensity  of  the  stimulus. 
It  is  not  assumed  that  the  violin  has  increased  in  in- 
tensity when  its  tones  are  picked  out  from  the  mass  of 
an  orchestra,  nor  is  it  assumed  that  the  tactual  sensations 
grow  weak  when  they  are  not  attended  to.  It  is  certain 
that  attention  and  intensity  are  sufficiently  different  in 
their  effect  upon  consciousness  to  prevent  them  from 
being  mistaken  for  each  other.  It  is  generally  asserted 
that  attention  increases  the  clearness  of  a  mental  state. 
The  state  becomes  clearer,  its  details  are  more  promi- 
nent, it  can  be  more  easily  used  and  understood.  This 
quality  of  clearness  is,  however,  different  from  intensity 
in  spite  of  the  fact  that  both  make  a  mental  state  more 
important. 

Analysis  and  Synthesis.  —  Analysis  and  synthesis  may 
both  be  referred  to  the  effect  of  selecting  different  states. 
In  analysis  some  one  part  of  a  total  process  is  made 
prominent,  and  this  makes  possible  the  recognition  of 
its  constituents.  As  one  attends  to  one  of  the  notes  of 
a  chord,  that  note  becomes  prominent  in  the  complex. 
Analysis  of  the  chord  consists  in  making  each  of  its 


CONDITIONS   OF   ATTENTION  11$ 

components  prominent  one  after  another.  Synthesis 
is  also  a  result  of  increasing  the  clearness  of  mental 
states.  It  differs  from  analysis  only  in  that  the  total 
effect  of  the  mass  is  attended  to  rather  than  some  one 
component.  With  the  chord  one  may  attend  to  deter- 
mine the  closeness  of  fusion  of  the  components  or  the 
pleasantness  of  the  compound.  This  serves  to  unite 
the  elements  into  a  single  whole.  The  results  of  atten- 
tion may  be  either  to  analyse  or  to  synthesise,  but  in 
either  case  the  primary  effect  is  to  increase  the  promi- 
nence of  part  or  of  whole.  This  change  in  clearness  with 
the  resulting  analysis  or  synthesis  may  affect  memory 
or  thought  processes  as  well  as  sensations.  One  may 
analyse  either  the  memory  or  the  sensational  elements 
from  a  perception,  or  one  may  turn  from  a  perception 
to  study  mental  imagery,  or  may  attend  to  one  part 
after  another  of  an  idea.  The  effect  upon  ideas  is  the 
same  .as  upon  sensations.  In  action,  selection  is  more 
likely  to  be  of  wholes  than  of  parts,  although  on  occa- 
sion one  element  of  a  complex  act  may  be  emphasised 
without  changing  the  others. 

The  Conditions  of  Attention.  —  Why  one  selects  or 
attends  is  not  so  easy  to  determine.  Usually  the  con- 
ditions are  hidden.  Attention  comes  without  antece- 
dent desire  or  warning.  One  often  finds  one's  self  at- 
tending without  any  preliminary  intention  and  even 
against  one's  will.  When  one  desires  to  attend,  in  ad- 
vance of  attention,  it  is  a  problem  why  one  desires, 
and  this  usually  escapes  notice  even  when  the  question 
is  raised.  Nearly  always  one  is  concerned  to  know  only 
that  one  desires  to  attend  and  does  not  care  to  know 


1 1 6        THE  ESSENTIALS  OF  PSYCHOLOGY 

? 

why.  Indirect  methods,  however,  have  thrown  con- 
siderable light  upon  the  conditions  of  attention.  These 
methods  consist  in  studying  the  circumstances  in  the 
individual  and  the  outside  world  that  precede  attention, 
and  in  generalising  the  results  of  the  observation  in  laws. 
In  the  light  of  these  observations  two  sets  of  conditions 
may  be  distinguished,  the  subjective  and  the  objective. 
The  one  is  a  series  of  circumstances  in  the  outside  world 
that  precedes  attention,  the  other  the  earlier  experiences 
of  the  individual.  These  conditions  may  be  first  deter- 
mined for  attention  to  external  stimuli,  although  the 
results  hold  for  all  selection. 

Objective  Conditions  of  Attention.  —  The  circum- 
stances in  the  outer  world  that  favour  the  entrance  of  a 
sensation  are  to  be  found  in  the  amount  of  energy 
exerted  by  the  stimulus  upon  the  sense-organ.  The 
amount  of  energy  expended  may  be  due  to  the  intensity 
of  the  stimulus,  to  its  duration,  or  to  the  area  of  the 
sense-organ  affected,  (i)  An  intense  sound  such  as  an 
explosion,  a  bright  light,  a  strong  odour,  will  force  them- 
selves upon  attention,  however  much  one  may  desire  to 
attend  to  something  else.  (2)  Similarly  a  large  object 
will  be  seen  where  a  small  one  might  escape  notice.  (3) 
Up  to  a  certain  point,  too,  the  greater  the  duration  of  a 
stimulus,  the  more  likely  it  is  to  enter  consciousness. 
Beyond  that,  greater  duration  leads  to  neglect;  one 
attends  and  passes  on  to  something  else,  and  the  stimulus 
is  no  longer  appreciated.  This  is  but  another  way  of 
stating  that  change  is  more  important  than  absolute 
intensity  or  extent  in  determining  the  course  of  attention. 
One  notices  a  whistle  of  changing  pitch  or  intensity  where 


CONDITIONS   OF   ATTENTION  1 17 

a  constant  one  would  escape  notice.  One  even  appre- 
ciates the  ticking  of  a  watch  as  it  stops,  although  the 
preceding  continuous  ticking  has  not  been  noticed  at  all. 
Similarly,  objects  that  move  towards  or  away  from  us 
are  noticed,  although  the  same  objects  would  escape 
notice  if  stationary,  and  our  only  way  of  knowing  that 
they  move  away  or  approach  is  from  the  changing  size. 
Change,  whether  in  size  or  intensity,  whether  it  be  in- 
crease or  decrease,  attracts  attention.  These  char- 
acteristics of  the  outside  world  that  tend  to  compel 
us  to  receive  a  sensation  may  be  said  to  be  opposed 
to  attention.  They  express,  not  the  selective  activity 
of  consciousness,  but  the  forces  in  the  outside  world 
that  oppose  voluntary  selection.  If  they  alone  acted, 
consciousness  would  be  but  a  plaything  of  external 
forces.  It  is  usual  to  extend  the  meaning  of  the  term 
attention  to  cover  all  the  factors  that  explain  the  entrance 
of  sensations,  and  one  cannot  understand  the  subjective 
factors  without  a  knowledge  of  these  objective  con- 
ditions, whether  one  calls  them  conditions  of  atten- 
tion or  not.  One  might  add  in  this  connection,  in 
anticipation  of  the  later  discussions,  that  there  are 
similar  objective  conditions  which  oppose  subjective 
control,  both  in  memory  and  in  action.  In  both,  these 
are  found  in  the  closeness  of  connection  between  sensa- 
tion or  idea  and  other  ideas  or  movements.  The  develop- 
ment of  the  laws  must  be  left  to  the  later  chapters. 

The  Subjective  Conditions  of  Attention.  —  The  sub- 
jective conditions  give  the  individual  spontaneity  and 
self-expression  in  the  selection  of  sensations.  They 
reflect  the  earlier  life  of  the  individual  in  very  much 


Il8        THE  ESSENTIALS  OF  PSYCHOLOGY 

the  same  way  that  the  objective  conditions  reflect  the 
outer  world  at  the  moment.  It  is  possible  to  enumerate 
five  factors  of  greater  or  less  generality  that  determine 
the  nature  of  attention.  Enumerated  in  the  order  of 
nearness  in  time  to  the  particular  act  of  attending, 
these  are :  (i)  the  idea  in  mind,  (2)  the  purpose  or 
attitude  at  the  moment,  (3)  the  earlier  education,  (4) 
duty  (as  the  expression  of  social  or  individual  ideals), 
and  (5)  heredity.  The  first  can  be  seen  either  in  the 
influence  of  an  immediately  preceding  sensation  or  of 
an  immediately  preceding  idea.  If  one  has  heard  or 
seen  or  is  thinking  of  some  object  and  that  object  pre- 
sents itself,  it  will  be  noticed  where  otherwise  it  might 
escape  attention.  It  is  easier  to  hear  an  overtone  if 
a  tone  of  the  same  pitch  has  been  heard  at  full  strength 
just  before.  Similarly,  in  listening  to  an  orchestra,  re- 
calling the  tones  of  a  violin  or  looking  at  the  violin  will 
be  certain  to  make  the  tones  of  that  instrument  promi- 
nent, when  otherwise  they  might  not  be  noticed.  If 
when  looking  for  an  object  one  will  hold  its  picture 
in  mind,  one  will  see  it  at  once.  When  a  bird  in  a 
tree  has  been  seen  once  through  a  glass,  it  will  con- 
tinue to  be  seen  easily,  although  it  may  have  been 
looked  for  in  vain  a  long  time,  before  it  was  first 
discovered. 

Mental  Attitude  a  Condition  of  Attention.  —  The 
second  of  the  subjective  conditions  of  attention  takes 
three  forms.  Each  is  an  expression  of  a  mental  attitude 
and  is  a  little  more  general  than  the  idea  or  sensation 
prominent  at  the  moment.  The  most  usual  and  most 
definite  way  of  arousing  the  attitude  is  to  ask  a  ques- 


CONDITIONS   OF   ATTENTION  IIQ 

tion.  This  may  be  illustrated  by  a  simple  experiment. 
Cut  a  number  of  bits  of  paper  of  different  shapes  and 
colours.  Cover  them  with  a  piece  of  cardboard  and 
expose  them  for  an  instant  as  you  ask,  '  What  colours 
do  you  see?  '  After  exposure  the  observer  can  tell 
pretty  accurately  what  colours  were  shown.  If  then 
you  ask  him  what  the  forms  were  or  how  many  bits 
were  shown,  it  will  be  found  that  he  can  give  no  correct 
answer.  One  sees  what  corresponds  to  the  question; 
all  else  is  excluded  from  consciousness.  Sometimes  the 
question  arises  spontaneously  or  is  suggested  by  a  sen- 
sation. You  wonder  if  it  is  raining,  and  as  you  look 
out  of  the  window  with  this  question  in  mind,  you  notice 
a  drizzle  or  see  spots  upon  the  roof  that  would  other- 
wise have  escaped  you.  Very  many  observations 
grow  in  this  way  out  of  specific  questions,  and  it  is 
surprising  to  note  how  certain  the  question  is  to  bring 
to  mind  any  object  that  may  contain  the  answer  to,  or 
correspond  to,  the  question,  and  how  little  one  sees  that 
does  not  correspond  to  some  question.  Most  people 
cannot  say  whether  the  four  on  the  watch  is  IIII  or 
IV,  because  they  look  for  the  time,  not  the  characters. 
Purpose  as  Mental  Attitude.  —  Next  in  order  of 
explicitness  of  conscious  anticipation  is  the  purpose. 
This  differs  from  the  formulated  question  only  in  that 
the  end  to  be  attained  is  less  definite  or  less  definitely 
formulated.  Often  one  first  has  a  vague  general  problem 
and  this  suggests  one  definite  question  after  another  and 
these  in  turn  control  the  specific  acts  of  attention.  Usu- 
ally one  has  some  definite  purpose  in  observation  as  in 
action,  and  this  serves  to  control  attention  even  when 


120        THE  ESSENTIALS  OF  PSYCHOLOGY 

there  is  no  definite  question  in  mind.  In  a  laboratory 
one  may  be  seeking  for  the  solution  of  some  problem 
with  no  definite  question  formulated.  Under  those 
circumstances  one  is  very  likely  to  notice  anything  that 
harmonises  with  the  purpose.  Similarly  one  notices 
animal  life  in  the  field  of  a  microscope  more  easily  in 
the  zoological  laboratory,  and  plant  structures  more 
easily  in  the  botanical  laboratory.  The  purpose  is  not 
very  insistent  in  these  cases  but  is  none  the  less  opera- 
tive. In  everyday  life  what  is  appreciated  corresponds 
very  closely  to  the  purpose,  whether  that  purpose  be 
serious  and  permanent  or  trivial  and  transitory.  On  a 
hunting  trip  one  is  set  for  the  perception  of  game,  as  in 
a  classroom  one  is  set  to  understand  a  lecture  or  hear  a 
question.  This  '  set '  constitutes  the  purpose,  and  is 
effective  even  when  not  kept  in  mind.  One  often  has 
still  less  definitely  conscious  '  sets.'  In  these  one  is 
not  aware  of  a  purpose  and  has  no  definite  question. 
The  bias  arises  from  some  previous  experience  and  is 
not  preceded  by  a  desire  to  see  one  thing  or  group  of 
things  rather  than  another.  Nevertheless  any  object 
that  corresponds  to  the  attitude  will  be  noticed  at  the 
expense  of  other  objects.  After  one  has  detected  escap- 
ing gas,  other  odours  often  will  be  noticed,  even  after 
all  thought  of  detecting  an  odour  has  vanished.  All 
three  of  these  factors  serve  to  quicken  attention  for  one 
group  of  things  rather  than  for  another,  and  together 
they  constitute  its  most  important  condition.  What 
does  not  correspond  to  the  attitude,  purpose,  or  question 
of  the  moment  is  not  admitted  to  consciousness,  and 
all  that  does  correspond  to  it  will  be  noticed,  no  matter 


CONDITIONS   OF   ATTENTION  121 

how  unfavourable  the  circumstances  in  other  respects. 
Practically  the  only  difference  in  the  three  sorts  of 
attitudes  is  to  be  found  in  the  degree  of  anticipation  of 
the  object  attended  to.  The  question  very  definitely 
foreshadows  the  object  to  be  seen;  the  purpose  gives 
only  a  general  idea  of  the  class  of  objects  to  be  expected ; 
while  the  attitude  is  not  at  all  conscious  and  gives  no- 
expectation.  The  attitudes  change  from  hour  to  hour,, 
and  even  from  moment  to  moment.  They  are  practi- 
cally the  only  occasions  for  the  shifting  of  attention. 

Education  as  a  Condition  of  Attention. —  The  influ- 
ence of  the  earlier  life  in  determining  the  general  charac- 
ter of  attention  is  as  marked  as  the  influence  of  the  atti- 
tude in  the  changes  of  its  temporary  character.  Two 
influences  of  education  may  be  distinguished.  First 
it  makes  certain  forms  of  attention  more  effective. 
The  skill  of  tea  and  wine  tasters,  the  keenness  of  the 
savage  for  following  a  trail,  are  due,  not  to  any  improve- 
ment in  the  sense-organ  through  practice,  but  to  train- 
ing in  attention.  In  every  sense  department  and  in 
every  sort  of  observation  one  comes  with  practice  to 
appreciate  differences  that  at  first  cannot  be  detected. 
One  important  result  of  any  sort  of  education  is  the 
increased  capacity  for  observation.  A  second  influence 
of  education  upon  attention  is  the  more  usual  one  of 
determining  the  stimulus  to  be  effective.  What  is 
seen  or  heard  is  usually  an  indication  of  the  character 
of  earlier  experiences.  If  a  man  enters  a  strange  room, 
he  will  notice  first  some  object  which  his  education  has 
prepared  him  to  see.  A  fisherman  will  notice  the  rod  on 
the  wall,  the  athlete,  the  mask  and  foil  or  the  lacrosse 


122        THE  ESSENTIALS  OF  PSYCHOLOGY 

stick,  the  scholar  will  see  the  books,  and  the  artisan  the 
implements  of  his  trade.  It  is  possible  to  determine 
what  a  man's  occupation  or  training  is  by  studying  the 
objects  he  observes  and  the  order  in  which  he  sees  them. 
Even  more  generally  one  will  hear  one's  own  name  when 
spoken  in  a  conversation  of  which  nothing  else  is  heard. 
Sometimes  education  acts  indirectly  by  preparing  ques- 
tions and  purposes;  often  education  acts  directly  — 
one  is  not  aware  of  any  preliminary  purpose.  In  brief, 
education  gives  capacity  for  discrimination  and  also 
determines  the  order  in  which  presented  objects  shall 
enter  consciousness,  and  whether  they  shall  enter  at  all. 
Social  Determinants  of  Attention.  —  One  effect  of 
education  upon  attention  is  important  enough  for  sepa- 
rate mention.  This  is  the  effect  of  social  training  which 
serves  to  hold  attention  to  the  momentarily  unpleasant 
for  the  attainment  of  future  benefits.  One  is  con- 
stantly being  taught  that  certain  things  must  be  attended 
to  in  spite  of  the  fact  that  others  are  more  in  harmony 
with  the  momentary  mood.  It  is  of  course  not  possible 
to  analyse,  in  their  completeness,  the  forces  that  make 
for  this  sort  of  attention,  but  so  far  as  they  can  be  ana- 
lysed they  may  be  referred  to  social  influences  and 
be  brought  together  under  the  term  social  pressure. 
One  ordinarily  works  for  the  object  at  present  less 
pleasant  to  gain  some  greater  remote  good.  The  value 
of  the  remote  good  is  learned  from  and  usually  enforced 
by  society,  and  enforced  as  a  duty,  not  as  a  good.  The 
impulse  to  work  for  it  is  given  through  ideals,  and  the 
ideals  can  be  traced  to  the  society  of  the  individual. 
The  boy  of  to-day  seeks  to  avoid  manual  labour  and  to 


CONDITIONS   OF   ATTENTION  123 

enter  the  professions,  even  when  they  are  relatively  un- 
remunerative,  because  of  the  small  esteem  in  which 
working  with  the  hands  is  held  by  society.  Each  ideal 
demands  for  its  attainment  holding  attention  for  a 
long  time  to  matter  that  is  not  pleasant.  When  you 
turn  from  reading  a  novel  to  this  chapter,  you  are 
governed  by  social  pressure.  First  is  the  pressure 
exerted  by  teacher  and  class  to  stand  well,  and  then  the 
desire  to  attain  the  end  for  which  this  knowledge  is  a 
preparation.  Both  ends  are  desirable  in  the  last  analy- 
sis because  of  the  social  approval  they  receive.  The 
punishment  of  failing  to  attend  is  social  contempt ;  the 
reward  of  persistent  attention  is  social  approval.  Society 
sets  the  end,  social  pressure  compels  one  to  attend  for 
its  attainment.  The  attention  that  comes  from  social 
pressure  is  distinguished  from  the  other  forms  of  atten- 
tion due  to  education  in  that  the  end  and  the  process 
are  unpleasant,  and  attending  seems  the  result  of  effort, 
while  in  the  others  the  end  and  process  are  pleasant  and 
are  interesting. 

Heredity  and  Attention.  —  To  understand  certain 
characteristics  of  attention  we  must  go  back  of  the 
experience  of  the  individual  to  his  original  nature.  This 
is  determined  first  by  the  evolution  of  the  race  and 
second  by  the  immediate  heredity  of  the  individual. 
The  first  explains  the  fact  that  all  are  attracted  by  move- 
ment and  by  individuals  of  the  opposite  sex,  and  that 
love  stories  and  stories  of  fighting  universally  hold  us. 
Under  the  second  fall  the  differences  in  taste  shown  by 
individuals.  Liking  for  music  or  art  goes  back  in  part 
to  a  tendency  to  observe  certain  stimuli  rather  than 


124        TSE  ESSENTIALS  OF  PSYCHOLOGY 

others.  Many  similar  characteristics  and  capacities 
must  be  explained  in  large  part  by  innate  differences 
in  attention.  It  is  still  impossible  to  say  how  far  any 
particular  act  of  attention  is  due  to  an  hereditary  influ- 
ence and  how  far  to  education  and  other  acquired  tend- 
encies. Certain  it  is,  however,  that  each  plays  an 
important  part.  The  more  fundamental  ways  of  attend- 
ing are  hereditary. 

The  Nervous  Basis  of  Attention.  —  In  harmony  with 
our  preliminary  statement  that  all  mental  action  has  a 
corresponding  activity  in  the  cortical  cells,  it  is  neces- 
sary to  relate  the  conditions  of  attention  to  nervous 
processes.  The  nervous  basis  of  attention  is  undoubt- 
edly the  selective  preparation  of  certain  cortical  cells 
that  makes  excitation  easy.  This  preparation  is  a 
state  of  partial  activity  that  needs  but  to  be  increased 
by  the  stimulus  to  give  full  consciousness.  In  conse- 
quence a  stimulus  too  weak  to  affect  cells  not  thus 
prepared  will  arouse  these  to  full  activity.  Each  of  the 
conditions  discussed  above  may  be  traced  to  some  prepa- 
Tation  of  this  sort.  The  influence  of  the  immediately 
preceding  stimulus  is  to  leave  the  cells  it  excites  in  a 
state  of  partial  activity ;  they  are  still  quivering  from  the 
earlier  stimulation,  and  so  respond  easily  to  the  new 
stimulus.  The  influence  of  the  question  or  purpose  is  to 
arouse  in  some  slight  degree  a  whole  group  of  connected 
cells.  When  a  question  is  asked,  the  nervous  impulse 
spreads  from  the  cells  excited  by  the  question  to  others 
that  have  previously  been  excited  in  the  same  connec- 
tion. An  object  appealing  to  any  one  of  these  cells 
will  "Tnd  entrance  to  consciousness  made  easy  for  it. 


INTEREST  125 

Part  of  the  work  has  already  been  done.  The  influence 
of  education  is,  first,  to  connect  the  nerve-cells  into 
large  groups,  and  so  to  prepare  for  questions  and  pur- 
poses, and  secondly,  to  make  possible  the  spread  of 
preparation  from  group  to  group,  and  thus  to  determine 
the  course  of  the  spread  of  preparation.  It  probably 
also  makes  certain  paths  permanently  more  permeable, 
and  so  more  open  to  excitation  than  they  were  in  advance 
of  training.  The  hereditary  bias  has  a  similar  explana- 
tion, except  that  the  selective  permeability  is  present 
in  advance  of  training.  Preliminary  preparation  in 
the  nervous  system  is  correlated  with  selection  of  sen- 
sations in  consciousness,  and  each  of  the  conditions  of 
selection  induces  in  the  nervous  system  a  state  of  partial 
activity  which  prepares  for  full  activity. 

Interest  and  Non-voluntary  Attention.  —  The  condi- 
tions of  attention  can  be  reduced  to  certain  peculiarities 
in  the  outside  world  and  to  different  events  in  the  life 
of  the  individual.  But  if  one  should  ask  the  average  non- 
scientific  individual  why  he  attends,  he  would  answer 
in  practically  every  case  that  he  attended  because  he 
was  interested  or  because  he  made  an  effort.  If  we 
examine  our  own  consciousness,  it  is  evident  that  atten- 
tion from  interest  and  attention  from  effort  are  nat- 
ural divisions.  It  is  desirable  to  refer  this  popular  ex- 
planation and  classification  to  the  conditions  already 
discussed.  A  list  of  the  things  that  are  interesting 
includes  those  that  are  attended  to  naturally  and  uni- 
versally, such  as  stories  of  conflict.  Attention  to  these 
we  have  seen  to  be  due  to  heredity,  to  education,  or  to 
passing  attitude  or  purpose.  Some  interests  are  general 


126        THE  ESSENTIALS  OF  PSYCHOLOGY 

and  innate,  some  are  acquired  by  education,  and  some 
are  temporary  and  seem  to  come  and  go  without  cause. 
To  say  that  attention  is  due  to  interest  is  merely  to  say 
that  it  is  due  to  some  one  of  the  subjective  conditions 
other  than  social  pressure.  Attention  from  these 
conditions  is  pleasant  and  spontaneous.  It  has  some- 
times been  called  non- voluntary  attention. 

Effort  and  Voluntary  Attention.  —  Attention  due  to 
effort  falls  almost  universally  under  the  socially  condi- 
tioned. When  one  is  said  to  strive  to  attend,  the  incen- 
tive is  ordinarily  some  ideal  of  social  origin.  The  real 
occasion  for  attending  is  the  social  approval  that  is 
expected  or  the  blame  that  is  feared  if  one  fails  to  attend. 
The  social  incentive  is  generally  given  the  name  duty. 
This  sort  of  attention  is  also  marked  off  from  the  others 
by  the  accompanying  diffuse  contractions  in  different 
parts  of  the  body  that  give  sensations  of  strain.  These 
constitute  the  feeling  of  effort.  Attention  induced  by 
ideals  of  social  origin  and  accompanied  by  effort  is  called 
voluntary  attention. 

Involuntary  Attention.  —  Attention  conditioned  by 
the  nature  of  the  stimuli  from  the  external  world  com- 
pletes the  list.  This  is  called  involuntary  attention, 
since  it  may  be  opposed  to  the  purpose  and  to  the  domi- 
nant ideals  of  the  moment.  It  is  always  effortless,  but 
may  or  may  not  be  interesting.  To  exclude  these 
stimuli  is  the  usual  object  of  effort.  We  may  say  that 
there  are  three  sorts  of  attention :  voluntary,  non-volun- 
tary, and  involuntary.  Voluntary  attention  is  condi- 
tioned by  social  pressure  and  is  accompanied  by  effort ; 
non-voluntary  attention  is  conditioned  by  the  idea  in 


ATTENTION   AND   MOVEMENT  127 

mind,  the  mental  attitude  of  the  moment,  education, 
or  heredity,  and  is  accompanied  by  interest;  involun- 
tary attention  is  conditioned  by  the  character  of  the 
stimuli  that  are  presented,  and  either  is  accompanied  by 
interest  or  is  attention  to  the  distraction  that  should  be 
resisted  and  so  through  conflict  gives  occasion  for  effort. 
The  different  forms  cannot  always  be  distinguished,  but 
they  serve  the  practical  purposes  of  classification. 

The  Motor  Phenomena  of  Attention.  —  Movements 
are  among  the  most  striking  characteristics  of  the 
attentive  consciousness.  They  serve  as  the  only  sign 
of  attention  to  the  onlooker,  and  are  prominent  in  the 
experience  of  the  individual  attending.  As  one  attends, 
the  various  sense-organs  are  adjusted  to  receive  the 
impression  most  effectively.  When  one  attends  to  an 
object  in  the  field  of  vision,  the  eyes  spontaneously 
turn  toward  it,  the  two  eyes  converge  that  it  may  be 
seen  with  the  fovea  in  each  eye,  and  the  lens  is  adjusted 
to  give  the  clearest  possible  image.  The  turning  and 
converging  of  the  eyes  can  be  seen  by  the  observer. 
One  knows  when  talking  to  a  person  whether  one  is 
being  looked  at  or  whether  the  gaze  is  directed  beyond 
and  infers  from  that  the  degree  of  attention  one  is  receiv- 
ing. This  is  the  most  common  indication  of  the  nature 
of  the  thing  attended  to.  Not  only  is  there  a  charac- 
teristic position  of  the  eyes  for  attention  hi  the  field 
of  vision,  but  for  hearing  also  and  even  for  touch  and 
taste.  Attention  to  objects  perceived  by  the  other 
senses  is  usually  followed  by  visual  attention  to  the  same 
object.  When  one  hears  a  sound,  one  turns  the  eyes 
toward  it,  and  when  touched,  one  looks  to  see  what 


128        THE  ESSENTIALS  OF  PSYCHOLOGY 

is  against  the  skin.  There  are  definite  adjustments 
of  the  other  senses  to  give  the  best  condition  for  observa- 
tion. In  addition  to  the  adjustment  of  the  sense-organs 
essential  to  perception,  many  more  general  muscular 
contractions  accompany  attending.  One  of  the  most 
important  is  the  inhibition  of  all  movement.  When 
one  is  listening,  all  movements  cease;  even  those  that 
have  started  are  stopped  in  mid  course.  Any  sort 
of  strong  attention  causes  an  unintentional  cessation 
of  activity.  At  the  same  time  the  breath  is  held  mo- 
mentarily, the  heart  beats  faster,  and  other  changes  in 
circulation  may  be  noticed.  Quite  as  obvious  and 
more  important  from  the  conscious  side  are  numerous 
general  contractions  hi  voluntary  muscles.  In  any 
attending  the  muscles  everywhere  are  slightly  tense. 
In  marked  degrees  of  voluntary  attention  the  brow  is 
wrinkled,  the  muscles  of  the  jaws  are  set,  and  the  fists 
may  be  clenched.  All  of  these  are  to  the  observer  signs 
of  attention,  and  at  the  same  time  they  indicate  to  the 
man  who  attends  that  he  is  attending.  The  diffuse 
contractions  give  rise  to  the  strain  sensations  which 
constitute  the  feeling  of  effort  in  voluntary  attention. 
The  motor  processes  serve  to  adjust  the  sense-organs 
to  the  most  adequate  reception  of  stimuli,  —  holding 
the  breath  and  inhibiting  general  movements  prevent 
the  interference  of  distracting  sensations,  while  the  cir- 
culation is  adjusted  to  the  increased  demands  of  the 
organism.  On  the  other  side  they  indicate  to  the 
observer  that  the  man  is  attending,  and  to  himself  they 
give  some  idea  of  the  degree  of  attention  or  at  least  of 
the  amount  of  conflict  in  attention. 


ATTENTION  AND   MOVEMENT  I2(J 

Is  Attention  or  Movement  Primary?  —  Much  con- 
troversy has  arisen  in  the  last  few  years  as  to  whether 
attention  or  movement  is  primary.  One  theory  is  that 
attention  is  due  to  the  motor  response ;  the  other  that 
attention  is  first  and  the  response  a  mere  accompani- 
ment or  result.  The  truth  seems  to  lie  between  them. 
The  essential  fact  in  attention  is  the  selective  prepara- 
tion. Movements  of  accommodation  and  clearness  of 
conscious  states  are  both  results  of  this  preparation. 
The  preparation,  as  has  been  seen,  is  the  outcome  of 
the  preceding  activities  of  the  individual,  near  and 
remote,  and  of  the  effects  that  these  activities  have 
had  upon  the  nervous  organism.  The  effect  of  this 
preparation  as  expressed  in  the  attitude  toward  any 
stimulus  is  what  we  call  attention.  As  seen  by  the  in- 
dividual, this  is  marked  by  selection  of  stimuli  and  by 
clearness  of  certain  conscious  states.  As  seen  by  an- 
other, attention  is  a  series  of  movements,  a  visual  fixa- 
tion, a  bodily  attitude,  or  general  strain.  Of  the  effects 
of  the  preparation,  we  can  never  be  sure  whether  clear- 
ness or  movement  comes  first.  In  many  cases  it  can  be 
observed  that  the  stimulus  presents  itself  in  some  vague 
way  and  the  sense-organs  gradually  adjust  themselves 
to  give  greater  definiteness  of  impression.  This  is  the 
usual  order  in  involuntary  attention.  When  the  stimu- 
lus is  expected,  the  sense-organs  are  prepared  in  advance. 
In  that  case  preparation  is  usually  determined  by  some 
memory  process  which  precedes  and  initiates  movement. 
This  is  true  of  voluntary  and  of  certain  forms  of  non- 
voluntary  attention. 

Attention   Means    Preparedness.  —  Attention,   then, 


130  THE  ESSENTIALS   OF  PSYCHOLOGY 

means  neither  the  clearness  of  consciousness  nor  the 
movements  that  accompany  the  clearing  up  of  a  con- 
scious state,  but  fundamentally  the  condition  of  pre- 
paredness of  the  individual  and  the  organism  that  gives 
rise  both  to  the  change  in  consciousness  and  to  the 
movements.  This  preparedness  makes  for  selection, 
not  merely  of  sensations,  but  of  ideas  and  of  movements. 
These  have  the  same  conditions  and  the  same  accom- 
panying states  of  effort  and  interest.  One  is  interested 
in  mental  states  and  actions  as  one  is  interested  in  objects, 
and  one  feels  effort  in  holding  to  a  train  of  thought  or 
in  selecting  a  course  of  action  as  in  carrying  out  a  diffi- 
cult bit  of  reading  or  observation.  The  same  charac- 
teristics that  are  prominent  in  attention  are  prominent 
in  the  selection  of  thought  and  action.  The  fundamental 
phase  of  attention  is  the  preparedness  that  determines 
selection.  It  is  the  same  in  essence  as  the  factors  to  be 
discussed  later  which  control  thinking  and  action. 
This,  not  any  conscious  change  in  sensation  or  move- 
ment, is  what  must  be  emphasised  in  attention.  This 
preparedness  is  not,  however,  itself  conscious.  One  does 
not  know  that  one  is  likely  to  see  one  thing  rather  than 
another  until  one  sees  it,  and  one  does  not  know  that 
certain  movements  of  accommodation  are  coming  until 
they  are  made.  The  only  sign  of  the  change  that  has 
been  wrought  by  earlier  activities  is  the  effect  in  modify- 
ing selection  and  in  inducing  the  accompanying  actions. 
The  Duration  of  Attention.  —  Two  practical  questions 
arise  with  reference  to  attention.  The  first  is,  how  long 
any  single  stimulus  may  occupy  the  dominant  place, 
the  second,  how  many  things  may  be  attended  to  at 


DURATION   OF   ATTENTION  13! 

once.  To  the  question  how  long  one  may  attend,  various 
answers  have  been  given.  The  ordinary  opinion  is  that 
one  may  attend  indefinitely.  One  seems  to  pay  atten- 
tion to  the  book  one  is  reading  for  hours  at  a  stretch, 
and  one  listens  to  a  lecture  for  an  hour  with  slight  dis- 
traction. In  all  such  cases,  however,  the  material  is  con- 
stantly changing,  one  is  not  attending  to  the  same 
stimulus,  nor  to  the  same  sensation  during  the  whole 
period.  If  one  attends  to  any  faint  stimulus,  the  ticking 
of  a  watch  or  a  faint  grey  ring  on  a  revolving  disk,  it  will 
be  seen  that  one  does  not  hear  the  sound  nor  see  the  ring 
all  the  time.  It  will  be  seen  for  a  second  or  two,  will 
vanish  for  four  or  five  seconds,  and  then  appear  again. 
The  total  length  of  the  cycles  will  be  about  six  to  ten 
seconds.  These  alternations  are  often  called  attention 
waves.  More  recently  they  have  been  referred  to  some 
periodical  change  in  the  sense-organ  or  in  the  nervous 
system,  so  are  not  to  be  regarded  as  changes  in  atten- 
tion in  the  narrowest  sense.  We  must  find  some  other 
answer  to  the  question  how  long  one  may  attend.  While 
watching  the  faint  ring  to  see  when  it  comes  and  goes, 
one  is  aware  of  a  constant  shifting  of  attention.  One 
drifts  away  from  the  ring  to  wonder  whether  one  is 
attending  or  is  attracted  by  some  extraneous  matter  or 
thing,  and  often  the  change  in  the  sensation  comes  while 
thus  distracted.  A  record  that  has  been  made  recently 
of  the  maximum  time  that  attention  can  be  held  to  any 
single  stimulus  indicates  that  the  pulsations  are  very 
short  indeed.  If  one  attempts  to  keep  attention  fixed 
upon  a  single  point  in  a  picture,  it  will  be  found  that 
at  least  once  a  second  something  about  the  point  will 


132         THE  ESSENTIALS  OF  PSYCHOLOGY 

come  in  to  crowd  it  out  of  consciousness.  If  the  stimu- 
lus be  absolutely  simple  and  one  is  careful  to  record 
each  appearance  of  something  else,  it  seems  that  one 
can  hold  attention  strictly  to  a  single  thing  for  less  than 
a  second.  When  in  the  popular  sense  attention  is  given 
to  a  thing  for  an  hour  at  a  time,  attention  is  constantly 
shifting  from  part  to  part,  or  is  turning  to  other  objects 
or  thoughts  for  longer  or  shorter  periods.  Attention 
for  more  than  a  second  or  so  to  absolutely  the  same 
stimulus  is  either  impossible  or  results  in  the  pathological 
condition  of  hypnotism. 

The  Range  of  Attention.  —  The  question  how  many 
things  may  be  attended  to  at  once  has  also  been  variously 
answered  at  different  periods  in  the  history  of  psychology. 
The  first  statement,  on  purely  a  priori  grounds,  was  that 
a  unitary  mind  could  have  not  more  than  one  conscious 
process  at  one  time.  More  recently  experiments  dem- 
onstrated that  if  a  number  of  objects  were  shown  for 
one-fifth  of  a  second  or  less,  four  or  five  objects  might  be 
seen.  More  recently  still,  however,  careful  observation 
of  the  process  of  determining  the  number  of  objects 
shows  that  even  with  short  exposures  the  objects  are 
not  attended  to  at  once,  but  are  impressed  upon  con- 
sciousness and  persist  for  a  time  in  the  memory  after- 
image, where  they  may  be  attended  to  separately  and 
counted.  It  is  as  if  one  took  an  instantaneous  photo- 
graph of  a  group  of  objects  and  counted  them  on  the 
film  after  development.  The  memory  after-image  per- 
sists only  a  second  or  two,  however,  and  the  number  of 
objects  that  may  be  seen  with  a  short  exposure  depends 
upon  the  number  that  can  be  attended  to  and  counted 


RANGE   OF   ATTENTION  133 

before  the  image  disappears.  It  seems  probable  from 
all  the  experiments  that  only  a  single  object  may  be 
attended  to  at  once. 

Very  much  the  same  conclusion  has  been  reached 
about  the  related  problem  of  the  number  of  things  that 
may  be  done  at  once.  Often  two  or  more  operations  are 
apparently  carried  on  at  the  same  time.  Careful  in- 
vestigation, however,  shows  that  two  things  can  be  done 
at  once  only  if  one  has  become  so  habitual  as  to  require 
no  attention.  One  may  easily  carry  on  a  conversation 
while  walking,  but  in  this  case  walking  has  become  so 
automatic  that  it  requires  no  conscious  guidance.  Should 
the  way  become  very  rough,  conversation  will  cease 
or  will  suffer  long  and  frequent  interruptions.  Ex- 
periments have  been  made  to  show  that  one  can  read 
a  selection  and  add  a  series  of  figures  at  the  same  time 
more  quickly  than  one  could  do  both  in  succession,  but 
if  either  task  is  difficult  enough  to  require  full  attention, 
the  two  will  take  more  time  when  carried  on  together 
than  when  done  successively.  When  easy  and  familiar, 
one  task  will  be  carried  on  automatically  while  attention 
is  given  to  the  other,  but  when  both  require  full  atten- 
tion, only  one  can  be  carried  on  at  a  time  to  advantage. 

Attention  and  Inattention.  —  A  natural  question  arises 
as  to  what  the  opposite  of  attention  may  be,  or  whether 
there  is  ever  a  time  when  one  does  not  attend.  Com- 
plete inattention  is  noticed  only  during  sleep  or  periods 
of  unconsciousness.  Even  in  sleep  there  is  apparently 
some  selective  adaptation  to  stimuli.  A  sleeping  man 
will  be  aroused  by  his  name  even  if  spoken  in  a  tone  so 
low  that  he  has  heard  nothing  else  of  the  conversation. 


134  THE   ESSENTIALS   OF  PSYCHOLOGY 

In  profound  slumber  a  mother  is  '  set '  for  the  move- 
ments of  her  child,  the  nurse  for  the  patient.  In  the 
insane,  too,  attention  is  present  although  in  a  reduced 
or  distorted  form.  The  so-called  states  of  inattention 
of  the  normal  man  are  really  states  of  attention,  but  of 
attention  to  something  at  the  moment  undesired.  They 
divide  into  two  forms,  —  scattered  or  diffuse  attention, 
and  absent-mindedness.  In  the  one,  attention  is  con- 
stantly shifting  to  a  new  object,  and  no  one  is  kept  before 
consciousness  long  enough  to  be  fully  appreciated.  In 
the  other,  attention  is  so  absorbed  in  some  one  thing  or 
course  of  thought  that  other  sensations  have  little  chance 
to  enter.  The  first  form  is  more  frequent  in  childhood 
and  in  certain  pathological  states,  the  other  is  more 
usual  in  maturity  and  is  frequently  found  in  men  of 
more  than  usual  training  and  ability.  Both  forms  of 
inattention  are  desirable  if  not  in  excess ;  in  fact  they 
are  extremes  of  the  two  desirable  characteristics  of 
attention.  Attention  is  most  effective  when  all  useful 
objects  are  attended  to,  and  attention  is  kept  upon 
them  long  enough  to  appreciate  them  fully.  Dispersed 
attention  insures  entrance  of  all  important  objects,  the 
abstracted  state  protects  against  distraction  that  might 
prevent  full  understanding.  It  is  only  excessive  in- 
stability or  too  great  and  inappropriate  immersion  in 
anything  that  should  be  guarded  against. 

Attention  and  Distraction.  —  It  is  generally  thought 
that  any  distraction,  any  stimulus  that  may  present 
itself  at  the  time  one  is  endeavouring  to  attend  to  any- 
thing else  will  diminish  the  amount  of  attention  and  so 
render  observation  less  accurate.  Experiments  show 


ATTENTION  AND   DISTRACTION  135 

that  this  is  not  always  true.  If  one  is  comparing  two 
intensities,  e.g.  first  undisturbed  and  again  when  a 
phonograph  is  playing  near  by,  it  is  found  that  at  times 
the  judgment  made  during  the  distraction  may  be  more 
accurate.  Certain  individuals  and  all  individuals  under 
certain  conditions  seem  to  do  better  work  when  the  room 
is  not  too  quiet.  Much  depends  upon  the  strength  of 
the  distraction  and  the  health  and  attitude  of  the  in- 
dividual. Acts  that  require  a  very  short  time  are  less 
affected  than  those  that  occupy  more  time.  Recent 
experiments  by  Dr.  Morgan  offer  a  suggestion  that 
may  explain  the  apparent  contradiction.  He  asked  a 
number  of  students  to  press  a  certain  key  when  one  of 
a  number  of  colours  appeared  upon  a  disk  and  to  press 
another  key  when  another  colour  appeared,  etc.  Other 
complications  were  introduced  which  demanded  very 
close  attention.  The  quickness  of  mental  processes 
was  measured  by  the  time  required  to  make  the  re- 
sponse. Simultaneous  records  were  taken  of  the  pres- 
sure exerted  upon  the  key,  and  of  the  depth  of  breath- 
ing. The  task  was  performed  first  without,  then  with, 
distraction.  In  most  subjects  the  distraction  at  first 
caused  a  decrease  in  the  quickness  and  accuracy  of  work, 
but  this  soon  changed  to  an  increase  in  effectiveness. 
Study  of  the  records  of  breathing  and  of  the  pressure 
exerted  upon  the  key  showed  that  while  the  distraction 
acted,  the  key  was  pressed  harder,  the  breathing  was 
deeper,  and  that  slight  vocal  movements  were  used  to 
aid  in  thinking  of  the  movement  to  be  made.  The 
apparent  explanation  of  the  effect  of  distraction  in  the 
light  of  the  results  is  that  the  individual  exerts  himself 


136        THE  ESSENTIALS  OF  PSYCHOLOGY 

to  overcome  the  distraction  and  puts  forth  more  than 
enough  extra  effort  to  overcome  it  and  in  consequence 
does  more  than  before,  but  at  the  expense  of  extra 
fatigue. 

The  Genesis  of  Attention.  —  Attention  must  be 
present  in  the  child  in  some  form  from  the  very  earliest 
months ;  the  change  with  years  is  primarily  in  the  con- 
ditions that  control  selection  and  the  constancy  with 
which  attention  is  kept  upon  one  object.  At  first,  se- 
lection must  be  controlled  by  the  external  stimuli  and 
heredity.  The  infant  is  attracted  by  intense  stimuli  of 
any  sort  and  by  moving  objects.  Very  early,  experience 
shows  its  effect  and  the  child  begins  to  notice,  in  the 
chaos  of  the  new  and  unfamiliar,  objects  that  have  been 
seen  frequently.  From  this  time  on,  each  experience 
prepares  the  way  for  a  new  experience.  The  effect  of 
these  experiences  is  determined  by  the  closeness  of  the 
relation  of  the  experience  to  inherited  tendencies.  When 
they  oppose  heredity  the  effect  is  slighter  than  when  they 
aid  it.  At  this  stage  the  development  of  interests  be- 
gins. These  are  to  grow  with  all  learning  and  all  ex- 
perience and  must  change  and  develop  with  each  new 
experience.  With  .the  school  years  or  earlier  comes  the 
appreciation  of  duty  and  other  rudimentary  social  de- 
mands. At  this  stage  the  child  makes  a  beginning  in 
keeping  attention  fixed  upon  the  more  unpleasant  thing 
which  is  approved  by  society  in  the  face  of  the  more 
pleasant.  Training  in  attention  of  this  sort  comes  at 
first  through  seeing  the  advantages  of  attending  in 
harmony  with  social  ideals  as  enforced  through  dis- 
cipline. Later,  obedience  to  the  calls  of  duty  becomes 


SELECTION  AND   CONTROL  137 

more  or  less  habitual  and  the  habit  constantly  grows 
and  changes  through  application  in  new  fields.  In 
terms  of  our  classification,  attention  begins  with  the 
involuntary  and  the  hereditary  sort  of  non-voluntary 
attention ;  soon  the  other  non-voluntary  forms  develop  ; 
and  last  of  all  the  voluntary. 

Summary.  —  As  sensations  constitute  the  primary 
structures  of  consciousness,  so  attention  or  selection  is 
the  primary  function.  It  is  possible  to  select  sensations, 
memories,  and  actions.  The  conditions  that  lead  to  the 
selection  are  the  same  in  each  case.  They  are  to  be 
found  in  the  intensity  of  the  stimuli,  the  strength  of  the 
memory  or  the  habit  on  the  one  side,  and  in  the  mo- 
mentary attitude,  education  and  heredity,  and  social 
pressure  on  the  other.  Selection  in  any  one  of  these 
fields  is  accompanied  by  interest  if  conditioned  by  edu- 
cation or  heredity,  and  is  accompanied  by  diffuse  strain 
sensations  that  give  rise  to  the  feeling  of  effort  if  the 
selection  is  controlled  by  duty.  The  act  of  selection 
is  called  attention  when  applied  to  sensations;  it  is 
called  voluntary  control  of  ideas  when  applied  to  recall ; 
and  is  called  will  when  applied  to  action.  So  far  we 
have  considered  explicitly  only  the  control  of  sensation, 
although  what  has  been  said  here  of  conditions  and  ac- 
companiments holds  of  the  other  processes  as  well,  as 
will  be  made  clear  in  due  time.  It  should  be  emphasised 
that  the  terms  used  to  describe  the  fact  are  less  important 
than  the  fact.  The  fact  of  selection  is  called  will  in 
many  of  its  applications,  as  it  has  been  called  attention 
in  this  chapter.  There  should  be  no  quarrel  as  to 
whether  will  or  attention  is  the  more  important,  as  each 


138        THE  ESSENTIALS  OF  PSYCHOLOGY 

is  but  a  word  used  to  designate  different  applications 
of  this  fundamental  process  with  its  conditions  and  ac- 
companiments. The  fact  is  essential,  the  name  is  a 
matter  of  usage.  We  shall  make  use  of  the  fact  in 
connection  with  all  mental  operations. 

QUESTIONS 

1 .  Give  an  instance  of  the  way  sensations  are  selected.    Do  the 
sensations  that  are  not  selected  enter  consciousness?    If  so  how 
do  they  differ  from  those  which  are  selected? 

2.  What  is  the  motive  for  attending  to  a  musical  selection? 
To  solving  these   problems?    To  a  loud  noise?    Why  do  you 
notice  your  own  name  whenever  it  is  seen  on  a  page?    Trace 
the  acts  of  attention  to  the  conditions  mentioned  in  the  text. 

3.  Cite  instances  of  attention  that  are  due  to  each  of  the 
subjective  conditions. 

4.  Are  the  movements  which  accompany  an  act  of  attention 
its  cause  or  its  effect  ?     Give  evidence  in  favor  of  your  opinion. 

5.  Is  interest  cause  or  effect  of  attention?     What  is  inter- 
est?   In  what  sense  is  it  a  condition,  in  what  sense  a  mental 
state? 

6.  Answer  the  same  questions  for  effort. 

7.  Outline  the  changes  in  the  nervous  system  that  explain 
selection.    Are  they  the  same  for  all  conditions? 

8.  Is  distraction  ever  favorable  to  mental  work? 

EXERCISES 

i.  Paste  five  bits  of  paper  of  different  shapes  and  colours  and 
four  letters  upon  a  square  of  cardboard.  Show  it  to  a  group  with 
the  request  to  tell  what  colours  they  see.  Note  the  answers. 
After  an  interval  of  half  an  hour  ask  what  the  shapes  of  the  coloured 
papers  were;  then  what  letters  were  seen.  Compare  the  per- 
centages of  objects  seen  that  corresponded  to  the  questions  with 
those  which  did  not. 


SELECTION  AND  CONTROL  139 

2.  Look  closely  at  a  point  on  an  evenly  illuminated  and  coloured 
wall.     Can  you  distinguish  any  difference  in  the  intensity  or  bright- 
ness of  the  point  looked  at  as  compared  with  the  surrounding 
areas?     Have  an  assistant  strike  several  notes  upon  some  instru- 
ment.   Attend  first  to  one  then  to  another.    Does  the  attending 
increase  the  apparent  intensity  of  the  tone  or  merely  increase  its 
clearness  ? 

3.  Recall  as  definitely  as  you  can  some  act  of  attention  that  in- 
volved effort.     Can  you  analyse  the  components  of  the  feeling  of 
effort  ?    Lift  a  heavy  weight  that  also  requires  effort.     Is  the  qual- 
ity the  same  as  in  the  effort  of  attention  ?     Can  you  trace  the  feel- 
ing to  any  sense-organ? 

4.  Watch  a  small  dot  so  far  away  that  it  can  just  be  seen.     Can 
you  see  it  all  the  time?    How  many  times  a  minute  does  it  come 
and  go? 

5.  Try  to  keep  attention  upon  a  dot  when  near  enough  to  be 
seen  easily.     Can  you  watch  it  all  the  time?    Keep  a  list  of  the 
memories  or  other  sensations  that  come  in  to  crowd  it  out.    How 
many  times  will  attention  wander  from  it  and  come  back  to  it  in 
ten  seconds? 

6.  Have  an  assistant  prepare  a  set  of  cards  with  different  num- 
bers of  dots  upon  them.    Let  him  place  the  cards  face  down  upon  a 
table  and  show  them  one  after  another  for  an  instant  by  turning 
them  over  and  back.    What  is  the  largest  number  of  dots  that  may 
be  seen  at  a  single  glance  ?     Do  you  count  them  during  the  expo- 
sure or  from  memory  later? 

7.  Try  counting  from  20  downward  and  at  the  same  tune  write 
the  digits  from  i  up  to  20.    Take  the  time.    Take  the  time 
required  for  each  separately.     Compare.    Introspect  to  explain 
the  difference  in  time  required. 

8.  Add  a  column  of  two-place  figures  while  the  room  is  quiet 
and  all  is  favourable.    Add  a  second  column  of  the  same  difficulty 
while  an  electric  bell  is  ringing  continuously.     Add  while  two 
people  are  having  a  conversation  near  you.     Compare  times  and 
errors  under  the  three  conditions. 


140        THE  ESSENTIALS  OF  PSYCHOLOGY 

REFERENCES 

PILLSBURY  :  Attention,  chs.  i-v. 

ANGELL  :  Psychology,  ch.  v. 

TITCHENER:   Elementary  Psychology  of  Feeling  and  Attention, 

chs.  v-vii. 

JAMES  :  Principles  of  Psychology,  vol.  i,  ch.  xi. 
SEASHORE  :  Elementary  Experiments  in  Psychology,  ch.  xiii. 
J.  B.  MORGAN  :   The  Overcoming  of  Distractions.    Archives  of 

Psychology,  35. 


CHAPTER  VI 
RETENTION  AND  ASSOCIATION 

The  Materials  of  Memory  and  Imagination.  —  Before 
we  can  regard  our  enumeration  of  the  elements  of  con- 
sciousness as  complete,  we  must  consider  those  due  to 
the  rearousal  of  earlier  experiences.  With  eyes  closed 
and  other  senses  unstimulated  one  still  has  conscious 
processes,  and  at  all  times  elements  not  derived  im- 
mediately from  sense-organs  mingle  with  the  sensations. 
You  may  now  recall  an  event  of  last  year,  although  the 
sense-organ  is  now  not  excited  at  all.  You  can  see  the 
landscape  in  its  original  colours,  can  reinstate  the  tem- 
perature of  a  summer  day  although  it  is  now  winter, 
may  in  fact  renew  all  of  its  features  at  will.  These  ex- 
periences in  their  ultimate  qualities  are  of  the  same 
character  as  the  sensations.  The  colours  are  the  spec- 
tral colours,  the  tones  are  the  tones  of  the  scale,  the 
cold  is  the  familiar  cutaneous  sensation.  They  come 
now,  however,  not  from  the  sense-organs,  but  are  ex- 
cited by  the  action  of  other  central  parts  of  the  nervous 
system.  To  indicate  the  similarity  in  quality  to  sen- 
sation and  the  fact  that  they  are  due  to  the  stimulation 
of  one  part  of  the  cortex  by  another,  these  elementary 
components  of  memories  are  sometimes  called  centrally 
aroused  sensations.  A  little  observation  and  reflection 
show  that  in  every  case  these  processes  ultimately 
141 


142        THE  ESSENTIALS  OF  PSYCHOLOGY 

originate  in  the  senses.  The  object  that  you  recall  is 
the  same  object  that  you  saw  last  year.  On  occasion 
you  may  compare  the  memory  of  the  object  with  the 
object  itself  and  assure  yourself  of  the  similarity.  Even 
when  the  image  represents  nothing  that  has  been  seen 
before,  the  elements  of  which  it  is  composed  are  of  the 
same  character  as  the  sensations.  The  elements  are 
merely  rearranged  in  new  combinations.  The  sensory 
qualities,  whether  peripherally  or  centrally  aroused,  are 
like  the  colours  upon  the  painter's  palette.  They  are 
relatively  few,  but  from  their  combinations  all  the  con- 
scious experiences  may  be  obtained,  as  the  artist  may 
paint  any  scene  with  his  few  colours.  All  the  centrally 
aroused  sensations,  the  elements  of  memory  and  imagina- 
tion, come  originally  from  the  senses.  They  are  retained 
in  some  way  and  reinstated  on  suitable  occasion.  An 
understanding  of  these  centrally  aroused  sensations  re- 
quires an  answer  to  three  questions :  (i)  how  are  they 
retained  and  where  are  they  between  the  time  of  en- 
trance and  of  their  reinstatement?  (2)  under  what  cir- 
cumstances do  they  return?  (3)  how  do  they  compare 
in  quality  with  the  original  sensations? 

Theories  of  Retention.  —  Theories  of  the  nature  of 
retention  have  varied,  from  the  metaphor  of  the  ancients 
that  mind  was  like  wax  on  which  impressions  might  be 
made  by  a  seal,  to  the  equally  crude  physiological  theory 
that  each  idea  was  kept  in  a  single  nerve-cell.  The  gen- 
erally accepted  theory  at  present  is  that  retention  is  a 
physiological  process  allied  to  habit.  Aristotle  sug- 
gested that  memories  were  due  to  the  repetition  on  re- 
call of  the  same  movements  that  were  made  when  the 


THEORIES   OF   RETENTION  143 

original  experience  was  first  received.  Of  course  his 
knowledge  of  the  physical  organism  was  not  sufficient 
to  carry  him  very  far  in  his  theory,  but,  with  allowance 
for  our  increased  knowledge  of  the  nervous  system,  his 
statement  does  very  well  to-day.  Our  present  formu- 
lation is  that  memory  consists  in  the  rearousal  of  the 
cortical  structures  originally  active,  or  in  the  reinstate- 
ment of  the  same  activity  that  was  involved  in  the 
original  experience.  Whenever  a  nerve-tract  is  aroused, 
some  change  takes  place  in  it  that  predisposes  it  to  act 
in  the  same  way  again.  What  is  left  in  the  nervous 
system  is  only  this  predisposition  to  renewed  activity, 
not  an  idea  or  other  conscious  process.  The  idea  comes 
only  on  the  rearousal  of  structures  as  a  result  of  the 
predisposition.  Between  the  first  appearance  and  the 
rearousal,  the  predisposition  gives  no  sign  of  its  presence. 
At  this  moment  you  are  not  conscious  of  the  memories 
that  might  be  recalled  on  suitable  occasions.  You  are 
not  at  present  aware,  e.g.  of  the  facts  you  learned  last 
night  in  preparation  for  to-day's  recitation,  although 
you  will  be  able  to  recall  them  perfectly  when  questioned 
about  them. 

The  Cortical  Seat  of  Memories.  —  The  memories 
probably  have  their  seat  in  the  same  regions  of  the 
cortex  that  are  active  in  the  original  perception.  In- 
juries of  a  sensory  area  usually  give  rise  to  loss  or  dis- 
turbance of  memories,  as  well  as  to  loss  of  the  capacity 
for  sensations.  In  addition,  injury  to  associatory  areas 
may  have  an  effect  upon  memories.  It  is  possible  that 
in  some  individuals  the  sense-organ  is  excited  as  well 
as  the  central  nervous  system,  and  that  part  of  the 


144        THE  ESSENTIALS  OF  PSYCHOLOGY 

memory  comes  from  the  retina,  or  from  the  skin  where 
the  impression  was  first  received.  The  muscles  originally 
excited  by  the  stimulus  may  also  be  in  slight  contraction 
during  the  memory,  may  add  their  quota  to  the  total 
consciousness.  All  of  the  structures  active  during  the 
original  experience  may  have  their  activity  renewed  in 
the  recall.  Since,  as  will  be  seen  later,  the  order  of 
occurrence  determines  the  order  of  recurrence,  it  seems 
probable  that  the  connections  formed  at  the  original 
experience  make  possible  recall  and  that  the  change 
in  the  nervous  system  is  in  the  synapse  or  point  of 
contact  between  neurones. 

Retention  a  Form  of  Habit.  —  In  this,  retention  is 
closely  related  to  habit.  Habits,  as  was  seen,  are  due 
to  the  establishment  of  connections  between  sensory 
and  motor  neurones  by  a  change  that  takes  place  at  the 
synapse.  After  these  have  been  connected  frequently, 
the  stimulus  tends  to  reinstate  the  act  whenever  it 
appears.  Retention  of  ideas  has  exactly  the  same  basis. 
The  cells  involved  in  the  ideas  also  act  together,  and 
this  activity  produces  changes  in  the  synapses.  When- 
ever one  of  the  ideas  presents  itself  again,  the  other  is, 
or  tends  to  be,  reinstated.  Not  merely  the  cortical 
elements  are  rearoused  in  memory,  but  the  whole  sensori- 
motor  tract  may  be  partially  active.  This  brings  the 
process  still  nearer  to  habit.  Memory  is  an  habitual 
response  in  which  the  greater  part  of  the  activity  is  in 
the  cortex.  The  activities  of  the  sense-organ  and  of 
the  muscles  are  subordinated  to  the  central  processes, 
while  in  habit  the  whole  sensori-motor  tract  is  active  in 
approximately  the  same  degree.  The  tendency  to  re- 


RETENTION  145 

peat  an  action  once  made,  or  the  tendency  for  neurones 
that  have  once  been  active  together  to  act  together 
again  when  either  is  aroused,  is  at  the  basis  of  both 
processes.  Thus,  when  a  stranger  enters  the  room,  I 
stand  because  the  sight  of  a  stranger  has  been  closely 
connected  with  rising.  But  at  the  same  moment  I 
recall  vividly  a  remark,  made  on  another  occasion,  by 
a  person  of  similar  appearance.  This  remark  has  been 
connected  with  the  sight  of  a  person  of  this  description, 
in  very  much  the  same  way  that  the  act  of  rising  has 
been  connected  with  the  entrance  of  a  stranger.  The 
thought  might  have  been  spoken  and,  then,  that  also 
would  have  been  a  habit.  The  only  difference  when 
it  is  merely  recalled  is  that  motor  accompaniments  are 
left  off.  In  all  else  it  is  as  much  a  habit  as  any  move- 
ment. 

After-image,  Memory  After-image,  and  Memory 
Image.  —  Retention  may  also  be  related  to  the  visual 
after-image.  The  after-image  is  the  effect  of  a  stimulus 
upon  the  retina  that  persists  for  a  short  time  after  its 
cause  has  ceased  to  act.  Cortical  cells  show  a  similar 
tendency  to  continue  in  action  for  a  period.  If  you  will 
glance  out  of  the  window  for  a  moment  and  then  close 
the  eyes,  you  will  notice  that  the  objects  you  saw  during 
the  momentary  glance  persist  for  a  few  seconds  with 
sufficient  definiteness  for  you  to  note  details  that  es- 
caped you  during  the  actual  observation.  This  is  the 
mental  photograph  mentioned  in  the  chapter  on  atten- 
tion as  rendering  possible  the  perception  of  more  than 
one  object  during  a  very  brief  exposure.  It  has  the 
same  explanation  as  the  positive  after-image.  Like  the 


146         THE  ESSENTIALS  OF  PSYCHOLOGY 

after-image  it  is  the  result  of  the  persistence  of  activity 
in  the  neurones  after  the  stimulus  is  removed.  It  is 
sometimes  called  the  memory  after-image  or  primary 
memory,  or  more  recently  the  perseveration  tendency. 
The  ordinary  memory,  or  reinstatement  after  the  primary 
memory  has  lapsed,  may  be  looked  upon  as  a  renewal  of 
the  same  activity  of  the  cells  that  was  induced  by  the 
stimulus  and  that  persisted  during  the  primary  memory. 
To-morrow  when  you  recall  what  you  saw  as  you  looked 
from  the  window,  you  will  induce  in  the  cortical  cells 
the  same  sort  of  activity  that  they  showed  when  you 
were  looking  and  during  the  memory  after-image. 

Recall  always  through  Associated  Experiences.  — 
The  answer  to  our  second  question,  how  centrally 
aroused  experiences  are  recalled,  is  found  in  the  laws 
of  association.  These  laws  assert  that  all  recall  is  due 
to  the  preceding  mental  process.  This  process  is  effec- 
tive in  calling  back  the  ideas  because  of  connections 
developed  between  them  at  some  earlier  time.  The 
idea  that  was  in  mind  a  moment  ago  and  the  idea  that 
it  recalls  now  must  have  been  experienced  together  at 
some  time,  if  the  one  is  to  recall  the  other.  The  initia- 
tion of  recall  by  these  earlier  experiences  and  connec- 
tions may  be  seen  in  any  train  of  ideas.  If  one  will 
record  the  elements  of  an  uncontrolled  train  of  thought, 
it  will  be  seen  that  each  element  is  connected  with  the 
following  by  virtue  of  the  fact  that  both  have  been 
experienced  together  at  some  time.  A  girl  passing  my 
window  suggests  the  house  I  saw  her  going  into  yester- 
day. That  suggests  the  stages  in  building  the  house; 
that,  in  turn,  the  sound  of  hammering  that  woke  me 


ASSOCIATION  147 

this  morning ;  and  this  again  the  protest  of  one  neigh- 
bour to  another  who  had  been  frequently  chopping 
kindling  wood  at  an  unreasonably  early  hour  in  the 
morning.  A  revery  of  this  sort,  when  started,  may 
run  through  successive  links  until  disturbed  by  some 
duty  or  other  distraction.  A  study  of  a  train  of  ideas 
will  show  that  each  member  of  the  train  has  been  con- 
nected with  the  preceding  and  succeeding  links  at  some 
earlier  period.  It  is  evident,  however,  that  in  the  train 
just  described,  the  connections  are  of  different  sorts 
and  are  due  to  different  earlier  connections.  The  first 
two  associates  are  the  result  of  observing  two  things  at 
the  same  time.  The  last  two  turn  about  an  element 
(the  sounds  of  hammering)  common  to  both  of  the 
terms,  although  the  terms  as  a  whole  have  never  been 
in  consciousness  together.  This  difference  makes  neces- 
sary a  classification  of  the  forms  of  connection. 

The  Laws  of  Association.  —  The  traditional  classi- 
fication of  association  has  been  traced  back  to  Aristotle. 
It  recognises  four  laws  of  association :  association  by 
contiguity,  by  succession,  by  similarity,  and  by  con- 
trast. The  first  two  classes  have  an  altogether  different 
explanation  from  the  last  two.  The  first  two  refer  the 
connections  to  the  relations  at  the  time  the  connections 
were  formed,  the  last  two  classify  by  the  nature  of  the 
experiences  at  the  time  of  recall.  Association  by  con- 
tiguity means  merely  that  if  two  objects  are  perceived 
at  the  same  time,  one  is  always  likely  to  enter  con- 
sciousness if  the  other  presents  itself.  Association  by 
succession  asserts  that  if  two  ideas  have  been  experi- 
enced in  succession,  the  second  will  be  suggested  by 


148        THE  ESSENTIALS  OF  PSYCHOLOGY 

the  first  \\henever  it  comes  to  consciousness.  In  the 
illustration  of  the  preceding  paragraph,  the  girl  suggests 
the  house  because  I  have  seen  them  together.  The 
best  illustration  of  successive  association  is  found  in  the 
ordinary  rote  learning.  Words  repeated  in  succession 
return  in  the  same  succession  when  the  first  word  is 
heard.  Association  by  similarity  includes  instances  of 
recall,  in  which  the  idea  suggested  is  in  some  way  similar 
to  the  preceding.  Such  is  found  in  the  building  of  the 
house  recalling  the  hammering  that  awakened  me,  or 
perhaps,  more  strictly,  the  connection  shown  when  the 
hammering  suggested  the  protest  of  a  neighbour  against 
a  disturbance  of  a  similar  kind.  Association  by  con- 
trast covers  the  cases  in  which  the  two  ideas  involve 
opposite  qualities,  as  when  black  suggests  white,  or  big, 
little. 

The  Neurological  Theory  of  Association.  —  These 
original  laws  of  association  are  merely  descriptive  of 
the  ideas  that  succeed  each  other  and  of  the  relations 
between  them.  The  laws  do  not  indicate  the  reasons 
for  the  succession  or  the  causes  for  the  entrance  of  the 
different  ideas;  they  serve  only  to  classify  the  connec- 
tions. If  one  ask  why  an  idea  recalls  the  one  that 
accompanied  or  succeeded  it,  one  must  be  referred  to 
the  study  of  the  nervous  system.  In  its  terms  our  law 
is  that  if  two  neurones  are  active  simultaneously  or  in 
immediate  succession,  some  connection  is  established 
between  them  of  such  a  character  that  if  one  be  excited 
in  any  way  the  excitation  spreads  to  the  other.  The 
point  of  connection  is,  as  has  been  said  frequently,  the 
synapse.  Just  as  in  habit,  the  excitation  of  two  neu- 


FORMS   OF   ASSOCIATION  149 

rones  at  the  same  time  or  in  close  succession  decreases 
the  resistance  of  the  synapse.  This  increased  closeness 
of  connection  makes  possible  the  spread  of  any  activity 
from  one  to  the  other.  When  one  learns  the  first  letters 
of  the  alphabet,  the  impulse  spreads  from  the  neurones 
corresponding  to  '  a '  to  the  neurones  corresponding 
to  '  b/  and  as  a  result  of  numerous  repetitions  the  two 
groups  grow  together  to  such  a  degree  that  whenever 
'  a  '  is  suggested,  the  excitation  spreads  to  the  neurones 
that  correspond  to  '  b/  and  they  are  excited  also.  The 
change  in  the  synapse  as  a  result  of  use  is  the  explana- 
tion of  association,  as  of  habit.  Association  by  con- 
tiguity and  succession  is  the  expression  of  this  simple 
and  familiar  neurological  function. 

Association  by  Similarity.  —  Not  so  immediate  is 
the  explanation  of  association  by  similarity.  Similarity 
is  not  itself  a  force,  nor  is  it  possible  to  find  simple 
physiological  correlates  for  it.  The  ordinary  idea  is 
not  a  simple  element  of  consciousness  but  is  a  complex 
of  many  centrally  aroused  sensations.  The  mechanism 
of  recall  consists  in  replacing  certain  of  the  elements 
of  the  first  idea  by  others  to  constitute  the  new  idea. 
Thus  the  replacement  of  the  idea  of  the  disturbing 
hammering,  by  the  idea  of  the  neighbour's  protest  at 
another  form  of  disturbance  under  the  same  circum- 
stances, may  be  regarded  as  due  to  a  shift  of  ideas  about 
'  early-morning-noise-that-disturbs-sleepers  '  as  a  centre. 
The  elements  that  have  to  do  with  hammering  in  build- 
ing the  house,  drop  out,  and  the  persisting  elements 
that  constitute  the  early  morning  disturbance  idea,  are 
retained.  These  by  the  law  of  contiguity  or  succession 


150  THE   ESSENTIALS   OF   PSYCHOLOGY 

waken  the  remaining  elements  of  the  incident  described 
by  my  neighbour.  The  whole  process  is  the  dropping 
out  of  certain  elements,  and  the  recall  by  those  remain- 
ing of  new  elements  that  have  been  connected  with 
them.  The  common  element  at  once  makes  possible 
the  entrance  of  the  second,  and  gives  similarity  to  the 
two  ideas.  If  this  be  translated  into  nervous  terms, 
the  first  idea  corresponds  to  the  action  of  a  considerable 
group  of  neurones.  The  shift  to  the  second  idea  con- 
sists, first,  in  the  cessation  or  diminution  in  the  activity 
of  certain  elements  of  the  mass,  while  others  continue 
to  act  with  full  intensity.  The  cells  that  continue 
active  rouse  to  activity  the  other  group  of  cells  with 
which  they  have  also  been  active  earlier,  and  with  that 
the  incident  of  the  protest  against  chopping  in  the  early 
morning  comes  to  consciousness.  The  simple  physio- 
logical laws  are  the  same  here  as  in  the  earlier  case; 
the  only  added  feature  is  the  dropping  out  of  some 
elements,  while  the  others  continue  active.  Wundt  has 
called  this  sort  of  recall  association  by  identity,  since 
it  is  the  identical  element  in  each  idea  that  determines 
the  course  of  recall  James  calls  the  process  focalised 
recall,  but  both  agree  on  the  essentials  of  the  process  as 
given  above. 

Units  for  Thought,  Complexes  for  Neurology.  —  Both 
sorts  of  association  involve  the  same  principle,  but  there 
is  a  slight  difference  in  its  application.  This  is,  that  use 
tends  to  connect  neurones,  or  that  mental  elements  that 
appear  together  tend  to  return  together.  The  apparent 
difference  between  the  two  classes  serves  merely  to 
emphasise  the  fact  that  ideas  are  neurologically  and 


FORMS   OF  ASSOCIATION  151 

psychologically  always  complex.  The  ideas  that  are 
recalled  by  contiguity  or  succession  are  not  simple,  but 
the  mass  of  elements  may  be  regarded  as  disappearing 
or  appearing  as  a  whole  rather  than  as  dissolving  one 
into  the  other,  as  in  the  so-called  association  by  simi- 
larity. In  both  cases  one  must  distinguish  between 
the  unit  for  thought  and  the  unit  for  physiological 
action.  For  thought,  the  idea  is  the  unit;  one  is  con- 
cerned only  with  things  and  with  their  representatives 
as  wholes.  Association  on  the  contrary  is  always  be- 
tween the  elements  that  correspond  to  the  activity  of 
neurones.  Their  connections  alone  determine  the  way 
in  which  ideas  shall  succeed  each  other,  and  how  they 
shall  dissolve,  one  into  the  other.  The  older  laws  oi 
association  considered  only  the  relations  between  the 
ideas  as  wholes ;  any  dynamic  explanation  must  con- 
sider primarily  the  connections  between  the  elements. 
They  explained  by  similarity  what  the  more  modern 
men  explain  by  the  shifting  of  associates  about  some 
persisting  element  as  a  core.  Both  are  true,  but  one 
is  a  description  of  the  ideas  after  the  recall,  the  other 
is  the  real  explanation  of  the  recall.  Of  the  two  sorts 
of  association,  it  is  probable  that  there  is  in  every  case 
something  of  the  gradual  disappearance  of  one  idea, 
and  the  gradual  reappearance  of  the  other.  In  general 
the  more  mechanical  sorts  of  recall,  the  effects  of  rote 
learning,  etc.,  involve  contiguity  and  succession,  while 
the  more  intelligent  forms  of  thinking  make  the  associa- 
tion by  identity  more  prominent. 

Association  by  Contrast.  —  Association  by  contrast 
of  the  older  schools  is  also  to  be  explained  as  due  either 


152-        THE  ESSENTIALS  OF  PSYCHOLOGY 

to  the  frequency  with  which  things  that  contrast  are 
perceived  together,  or  to  the  shifting  of  elements  about 
some  common  unit.  Probably  each  explains  certain 
instances.  The  contrast  in  many  cases  would  not  be 
noticed  unless  the  elements  were  in  consciousness  to- 
gether. Dark  is  appreciated  only  when  near  light, 
rich  only  when  experienced  with  poor.  On  the  other 
hand,  there  is  always  something  in  common  between 
contrasting  qualities.  Rich  does  not  contrast  with  dark, 
nor  light  with  small,  because  they  have  no  common 
qualities.  If  one  looks  to  the  real  causes  of  recall 
rather  than  to  a  description  of  the  ideas  that  succeed 
each  other,  association  by  contrast  is  really  an  instance 
either  of  association  by  contiguity,  or  of  association  by 
similarity.  All  recall  is  due  to  the  simple  fact  that 
ideas  that  are  in  consciousness  together  tend  to  return 
together.  The  various  classes  are  but  different  applica- 
tions of  this  one  principle. 

Selection  in  Recall.  —  While  recall  depends  upon  asso- 
ciation, it  is  still  a  question  why  one  rather  than  another 
of  the  many  possible  associates  comes  to  consciousness. 
Practically  every  idea  has  been  connected  at  some  time 
with  a  great  many  other  ideas,  but  at  any  one  time  it 
will  arouse  only  one  of  these  associates.  The  selection 
of  one  from  among  these  possible  associates  has  approxi- 
mately the  same  conditions  as  the  selection  of  sensations 
in  attention.  Here  again  we  may  divide  the  conditions 
into  two  classes,  objective  and  subjective.  Among  the 
more  mechanical  factors,  corresponding  to  the  objective 
conditions  of  attention,  we  find  the  influences  that  deter- 
mine the  strength  of  the  physiological  connection  between 


CONTROL   OF   ASSOCIATION  153 

the  neurones.  These  are  four  in  number:  (i)  the 
strength  of  the  original  excitation ;  (2)  the  number  of 
times  the  two  have  been  active  together ;  (3)  the  recency 
of  the  original  connection ;  and  (4)  primacy,  or  the 
novelty  of  the  experience.  A  first  impression  makes 
stronger  associations  than  later  ones.  The  intensity  of 
the  original  excitation  depends  upon  three  factors: 
(i)  upon  the  intensity  of  the  physical  stimuli  that  gave 
rise  to  the  original  experiences ;  (2)  upon  the  degree  of 
attention  that  was  given  at  the  time ;  and  (3)  upon  the 
emotional  condition  of  the  individual  at  the  time  of 
learning.  Your  own  experience  will  convince  you  that 
each  of  these  has  an  effect.  Two  weak  experiences 
will  be  less  likely  to  be  associated  than  stronger  ones. 
Much  more  important  is  the  effect  of  attention.  In- 
attentive reading  is  only  slightly  effective.  Attention 
at  the  moment  of  the  original  reading  may  make  faint 
impressions  more  effective  than  intense  impressions. 
In  fact  it  might  be  questioned  whether  the  intensity  of 
the  stimulus  had  any  effect,  except  as  it  served  to  attract 
attention.  The  effect  of  emotion  is  very  closely  related 
to  attention.  If  the  original  experiences  are  accom- 
panied by  marked  emotion,  the  likelihood  of  recall  is 
increased.  The  others  of  the  objective  conditions  of 
recall  require  little  comment.  The  strength  of  the  con- 
nection grows  regularly  with  repetitions,  and  falls  away 
with  the  lapse  of  time.  Of  two  associates,  the  one  first 
made  seems  to  have  an  advantage  over  the  other.  This 
is  one  explanation  of  the  fact  that  events  of  childhood 
are  more  frequently  recalled  than  those  of  later  life. 
Each  of  these  objective  conditions  is  effective,  because 


154        THE  ESSENTIALS  OF  PSYCHOLOGY 

each  helps  to  determine  the  strength  of  the  connection 
between  the  different  elements  in  the  nervous  system. 

Subjsctive  Factors.  —  While  these  objective  or  physio- 
logical connections  are  essential  to  all  recall,  and  play 
an  important  part  in  determining  the  selection  of  one 
from  many  associates,  they  cannot  be  the  only  determi- 
nants. Were  they  the  only  factors  in  the  selection, 
the  course  of  thought  would  show  no  flexibility  and  no 
spontaneity.  Only  one  associate  can  be  physiologically 
strongest  at  any  moment.  In  actual  experience  we 
have  an  idea  recalling  now  one  idea  and  now  another ; 
we  are  ever  and  anon  preferring  a  faint  associate  to  a 
strong,  an  old  to  a  new.  What  gives  this  variety  and 
flexibility  to  ideas  is  the  group  of  subjective  conditions. 
These  are  practically  the  same  as  the  subjective  condi- 
tions in  attention.  The  first  is  the  attitude  or  purpose 
of  the  moment.  If  you  are  solving  one  problem,  the 
associates  that  are  suited  to  that  problem  will  be  re- 
called;  if  you  are  solving  another  problem  and  have 
the  same  idea  in  mind,  it  will  recall  another  idea.  For 
example,  if  you  see  in  your  account  book  two  numbers 
written  one  above  the  other,  you  will  add  in  one  case, 
you  will  subtract  in  the  other.  Whether  you  add  or 
subtract  will  depend  upon  the  context,  upon  the  prob- 
lem that  is  set  you  by  the  earlier  stages  in  the  account- 
ing. If  you  are  dealing  with  two  expenditures,  you  add ; 
if  dealing  with  a  balance  and  an  expenditure,  you  sub- 
tract. In  this  case,  the  sum  is  one  idea  that  the  two 
numbers  might  suggest,  the  difference,  another,  and 
which  shall  enter  depends  upon  the  purpose  of  the 
moment.  Similarly,  if  you  read  a  series  of  adjectives 


CONTROL   OF   ASSOCIATION  155 

to  a  person  with  the  request  to  name  opposites,  you 
will  get  one  series  of  associates ;  if  you  ask  him  to  give 
synonyms,  you  will  get  another  series.  Here  you  set 
the  task,  and  it  leads  at  once  to  the  right  associate. 
Probably  in  most  cases  the  attitude  is  not  at  all  con- 
scious, is  not  appreciated  by  the  thinker.  When  asked 
in  a  class  in  psychology  what  is  a  sensation,  one  at  once 
thinks  of  the  psychological  definition.  The  same  ques- 
tion by  a  child  who  was  reading  the  headline  of  a  news- 
paper brings  to  mind  an  entirely  different  answer.  One 
is  not  aware  of  the  psychological  attitude,  but  it  is  sug- 
gested by  the  place.  The  sight  of  the  newspaper  gives 
the  newspaper  attitude  just  as  certainly  and  just  as 
unconsciously.  James  illustrates  the  influence  of  atti- 
tude by  the  effect  of  the  context  in  two  lines  of  verse. 
The  same  word,  when  it  occurs  in  different  lines,  will 
recall  different  associates.  Thus  the  word  ages  occurs 
in  the  two  lines  from  Locksley  Hall  — 

"  I,  the  heir  of  all  the  ages,  in  the  foremost  files  of  time  " 
and 

"  For  I  doubt  not  through  the  ages  one  eternal  purpose  runs." 

One  does  not,  however,  make  a  mistake  and  supply 
'  one  eternal '  after  the  '  ages  '  in  the  first  line,  nor  '  in 
the  .  .  .'  after  the  '  ages  '  in  the  second.  The  preceding 
words  and  the  general  purpose  in  quoting  insure  the 
recall  of  the  right  associates,  whether  strong  or  weak. 
The  wider  setting,  the  attitude  or  purpose,  directs  the 
course  of  recall. 

Social  Pressure  as  a  Control  of  Association.  —  Of  the 
other  conditions  that  were  seen  to  determine  the  selec- 


156        THE  ESSENTIALS  OF  PSYCHOLOGY 

tion  of  sensations,  education,  social  pressure,  and  heredity 
have  their  effect  in  the  control  of  recall.  Education  is 
harder  to  distinguish  from  the  preparation  of  connections 
here  than  in  attention.  Its  most  important  influence  is 
probably  in  grouping  experiences  that  may  be  aroused 
later  as  units,  and  so  constitute  the  basis  for  attitudes. 
An  attitude  or  purpose  is  very  largely  just  the  response 
of  an  entire  group  of  neurones  that  serves  to  facilitate 
the  recall  of  all  members  of  the  group  when  the  group 
as  a  whole  is  aroused.  One's  purposes  grow  out  of,  and 
are  dependent  upon,  training  and  education.  It  is  in 
preparing  for  these  attitudes  that  education  exercises 
its  most  important  influence  upon  the  selection  of  asso- 
ciates. Social  pressure  here,  as  in  attention,  is  the  most 
important  element  in  enforcing  duty.  One  is  held  to 
the  disagreeable  task  by  considerations  of  what  others 
would  think  if  the  work  be  not  finished,  when  it  would 
be  pleasanter  to  let  the  train  of  thought  wander  at  will. 
A  student  in  writing  an  exercise  wanders  away  for  a 
moment  in  a  day  dream,  but  as  soon  as  he  is  reminded 
of  the  task,  the  ideas  connected  with  the  writing  reassert 
themselves.  The  course  of  association  is  held  to  the 
task  until  the  work  is  completed.  The  considerations 
that  enforce  this  return  to  the  unpleasant  course  of 
thought  are  primarily  social.  It  is  probable  that  heredity 
has  some  influence  in  directing  the  course  of  thought. 
Thoughts  of  a  certain  kind  are  pleasant  because  of  the 
natural  endowment  of  the  individual,  just  as  certain 
objects  are  pleasant.  In  brief,  the  conditions  that  select 
one  associate  from  the  many  possible  ones  are  approxi- 
mately the  same  as  the  conditions  that  select  one  from 


CONTROL   OF   ASSOCIATION  1 57 

among  the  many  possible  sensations  that  present  them- 
selves in  the  outside  world. 

The  Physiological  Basis  of  the  Control  of  Ideas.  — 
The  physiological  explanation  of  the  action  of  the  sub- 
jective elements  upon  the  course  of  recall  must  be  found 
in  the  influence  of  masses  of  neurones  other  than  those 
involved  in  the  direct  arousal  of  the  memory.  Let  us 
assume  that  one  is  attending  to  a  pencil,  and  that  several 
associates  have  been  connected  with  it.  Let  us  assume 
that :  A  represents  the  neurones  involved  in  thinking 
of  the  pencil,  and  connected  with  it  are  B,  C,  D,  and 
E.  B  is  the  neurone  group  connected  with  the  idea  of 
graphite  mines ;  C,  with  the  thought  of  a  pen  ;  D,  with 
the  picture  of  a  cedar  forest ;  E,  with  the  memory  of  the 
shop  where  it  was  obtained,  etc.  Let  us  assume  that 
the  strongest  connection,  as  a  mere  physiological  process, 
is  with  the  shop,  but  that  you  are  writing  of  the  crystal 
forms  of  carbon.  The  neurones  corresponding  to  the 
means  of  obtaining  graphite  have  been  predisposed  to 
excitation  by  the  writing,  —  the  group  B  would  be  par- 
tially aroused.  The  preparedness  of  B  for  excitation 
from  this  other  connection  is  sufficient  to  overcome  the 
greater  physiological  strength  of  E,  and  you  think  of 
graphite  mines,  rather  than  of  any  of  the  other  things 
that  were  possible.  At  any  moment  the  course  of 
thought  will  be  determined  by  these  antecedent  and 
related  thoughts,  or  by  the  physiological  activities  that 
correspond  to  them. 

All  recall  depends  upon  associations  that  have  been 
formed  by  the  experiences  of  the  individual.  At  any 
moment  recall  is  limited  to  the  ideas  that  have  been 


158  THE   ESSENTIALS   OF   PSYCHOLOGY 

connected  with  the  idea  then  in  mind.  Of  the  many 
things  that  have  been  connected,  that  one  will  be  chosen 
whose  bonds  are  physiologically  strongest  or  which  is 
most  in  harmony  with  the  purpose  of  the  moment.  In 
many  cases  of  mechanical  recall  it  is  the  strength  of  the 
association  that  is  most  important  in  determining  the 
course  of  ideas,  but  in  ordered  thought  the  subjective 
conditions  are  more  prominent.  In  a  day  dream  the 
mechanical  associates  are  dominant;  in  writing  or  hi 
speaking  of  a  serious  sort,  the  attitude  and  the  problem 
will  predominate.  Even  in  connected  thinking  irrele- 
vant ideas  will  frequently  insert  themselves.  If  these 
are  carefully  examined,  it  will  be  seen  that  the  inter- 
jected irrelevant  ideas  are  introduced  because  of  the 
strength  of  the  objective  connection  between  them  and 
the  preceding  idea  in  the  train.  The  objective  con- 
nections are  sufficiently  strong  to  prevail  against  sub- 
jective control.  No  idea  can  be  recalled  unless  some 
idea  that  has  been  associated  with  it  is  present  at  the 
moment.  One  can  reinstate  ideas  only  through  their 
natural  antecedents.  This  causes  no  inconvenience,  be- 
cause one  does  not  ordinarily  feel  the  need  of  an  idea 
without  being  able  to  recall  it.  The  desire  for  recall  or 
the  occasion  for  the  desire  ordinarily  serves  as  a  sufficient 
suggestion  to  effect  it.  Given  the  old  connections  that 
make  possible  the  recall  of  different  ideas,  the  subjective 
conditions,  —  attitude  or  purpose,  social  pressure,  and 
heredity,  together  with  the  setting,  internal  and  external, 
—  select  from  the  possible  associates  the  one  that  suits 
the  need  of  the  moment. 

How  Memory  Images  are  Distinguished  from  Sen- 


MEMORY   IMAGE  AND   SENSATION  159 

sations.  —  The  elementary  qualities  of  memory,  im- 
agination, and  reasoning  are  very  similar  to  the  qualities 
of  sensations.  If  one  thinks  of  a  red  surface,  one  may 
have  an  image  in  every  respect  like  the  original  percep- 
tion. The  colour  is  red,  the  texture  of  the  surface  is 
the  same  as  the  texture  of  the  object;  but  while  the 
qualities  are  the  same  as  in  sensation,  there  are  nearly 
always  sufficient  differences  to  prevent  one  from  mis- 
taking a  memory  image,  -or  image  of  imagination,  for 
the  real  object.  That  this  mistake  is  not  made  more 
frequently  is  due  to  at  least  three  factors :  (i)  centrally 
aroused  sensations  are  ordinarily  less  intense  than  the 
real  sensations;  (2)  they  have  certain  characteristic 
qualitative  differences ;  (3)  they  do  not  harmonise  with 
the  objects  that  are  seen  at  the  moment.  The  first 
criterion  is  ordinarily  sufficient,  but  fails  when  the 
images  become  very  intense,  or  the  external  stimulus 
is  very  faint.  Such  great  vividness  of  the  images  comes 
only  rarely  and  usually  in  abnormal  individuals  or  under 
abnormal  conditions.  Faint  intensity  of  external  stimu- 
lation may  be  obtained  at  will.  In  a  series  of  experi- 
ments by  Kiilpe,  individuals  were  seated  in  a  dark  room 
and  were  told  that  at  a  given  signal  coloured  lights 
might  be  thrown  upon  a  screen.  Sometimes  these  were 
shown  and  sometimes  not.  They  were  asked  to  say 
whether  the  resulting  experience  was  subjective  or  ob- 
jective and  also  to  state  how  they  distinguished  the  real 
colours  from  those  merely  imagined.  Under  these  con- 
ditions, every  observer  made  mistakes.  Ordinarily  the 
mistakes  consisted  in  asserting  that  colours  were  seen 
when  none  were  shown.  The  merely  imagined  qualities 


l6o        THE  ESSENTIALS  OF  PSYCHOLOGY 

were  mistaken  for  objective  qualities.  When  questioned 
as  to  how  they  distinguished  one  from  the  other,  the 
observers  gave  a  list  of  the  characteristics  that  aided 
them.  The  subjective  processes  were  indefinite  in  out- 
line, were  thin  or  netlike,  they  moved  at  random,  they 
persisted  when  the  eyes  were  closed  and  moved  with  the 
eyes,  they  left  no  after-images.  The  real  sensations 
were  definite  in  quality  and  outline,  vanished  on  clos- 
ing the  eyes,  remained  stationary  as  the  eyes  moved, 
and  left  after-images.  The  differences  are  on  the  whole 
insignificant,  and  even  those  that  were  mentioned  were 
not  constant  for  all  individuals.  In  quality,  images  are 
not  very  different  from  sensations. 

More  important  as  a  means  of  distinguishing  one  from 
the  other  in  practice  is  the  harmony  of  images  with  the 
preceding  train  of  thought,  and  their  lack  of  harmony 
with  the  events  of  the  outside  world.  If  one  should 
look  up  suddenly  and  see  what  appeared  to  be  the  figure 
of  a  person  known  to  be  remote  but  whom  one  had  been 
thinking  about  just  before,  one  would  at  once  appreciate 
the  figure  to  be  an  image.  This  would  be  all  the  more 
certain  if  no  footsteps  had  been  heard,  and  the  wall 
could  be  seen  through  the  image.  The  figure  would  be 
seen  to  be  a  natural  result  of  the  thought  processes  but 
altogether  out  of  harmony  with  the  external  events. 
Reference  of  a  mental  process  to  a  central  or  peripheral 
origin  is  most  frequently  made  in  terms  of  the  degree  to 
which  it  fits  into  the  train  of  events,  although  intensity 
and  the  peculiar  penetration  or  vividness  of  the  sensation 
nearly  always  contribute  their  share. 

The  Projection   of  the   Memory  Image.  —  A    third 


TYPES   OF   IMAGERY  l6l 

criterion  is  often  furnished  by  the  direction  in  which 
memory  images  are  projected.  For  some  individuals 
the  image  will  be  directed  backward  if  centrally  aroused, 
as  opposed  to  the  ordinary  outward  and  forward  refer- 
ence of  the  real  visual  sensation.  Objects  when  recalled 
may  be  seen  as  if  they  were  on  a  surface  some  distance 
back  of  the  head.  Others  project  imagined  objects  to 
the  right  or  to  the  left.  Here  they  will  not  be  con- 
fused with  the  sensory  impressions.  It  is  possible  that 
images  can  be  projected  outward  and  forward  so  as  to 
have  a  position  among  objects  actually  seen.  One 
individual  always  sees  remembered  or  imagined  events 
projected  in  colours  upon  the  wall  of  the  room,  and 
many  can  give  these  images  any  desired  position  in  the 
visual  field.  These  are  mere  personal  idiosyncrasies. 
Where  the  central  processes  are  thus  habitually  given 
a  direction  different  from  that  given  sensations,  the 
direction  is  a  result  of  the  distinction  that  is  made, 
rather  than  a  means  of  distinguishing  them  from  ex- 
ternal objects.  The  decision  as  to  whether  the  process 
is  of  external  or  internal  origin  is  practically  always 
immediate  and  without  hesitation;  one  does  not  even 
appreciate  that  a  decision  has  been  made. 

Memory  Types.  —  While  the  memory  images  are 
in  general  like  sensations,  they  certainly  have  fewer 
qualities.  The  number  of  pure  colours  that  an  individ- 
ual can  recall  is  probably  limited  to  a  dozen  or  twenty, 
as  compared  with  the  one  hundred  fifty  or  two  hundred 
that  may  be  discriminated  in  the  spectrum.  The  quali- 
ties in  the  other  senses  are  similarly  limited.  Not  only 
are  the  remembered  qualities  of  any  one  sense  relatively 


l62  THE  ESSENTIALS   OF  PSYCHOLOGY 

few,  but  most  individuals  are  restricted  for  their  mem- 
ory material  to  two  or  three,  and  a  few  to  but  one  of 
the  senses.  Most  numerous  are  the  individuals  who 
remember  in  visual  terms.  A  visualiser  of  the  exclusive 
type  will  recall  only  the  pictures  of  objects.  As  he 
thinks  of  the  water  running  from  a  faucet,  he  can  see 
the  water  fall,  see  it  splash,  but  has  no  trace  of  the 
sound.  The  whole  event  is  noiseless  in  memory.  Every- 
thing that  he  remembers  must  be  translated  into  pic- 
tures. More  rare  is  the  auditory  memory.  Individ- 
uals of  this  type  lack  all  but  the  sounds  in  any  memory 
process.  An  event  will  be  recalled  only  in  terms  of  the 
sounds  that  were  connected  with  it.  In  other  individ- 
uals memories  are  restricted  to  the  movements  that 
were  made  in  connection  with  the  events.  These  move- 
ments may  be  memories,  or  the  movement  may  be 
partly  reinstated.  One  might  translate  the  sounds  of 
the  voice  that  one  desires  to  recall,  e.g.  into  the  move- 
ments necessary  to  imitate  them  and  so  represent 
the  voice  to  himself.  Smell,  taste,  and  the  other  lower 
senses  alone  would  not  suffice  to  recall  all  sorts  of  ex- 
periences; where  present  at  all  in  memory  they  are 
subordinate  to  one  of  the  forms  of  imagery  just  men- 
tioned. 

Verbal  Imagery.  —  Another  method  of  recall  which 
may  be  used  for  all  purposes  is  by  language.  Prac- 
tically every  experience  may  be  and  is  expressed  in 
words,  and  most  individuals  use  words  very  generally 
in  thinking  as  in  talking.  Much  of  thought  is  anticipa- 
tory speech.  This  form  of  reproducing  or  imagining  is 
known  as  '  inner  speech.'  Inner  speech  might  con- 


TYPES   OF   IMAGERY  163 

ceivably  be  present  in  the  form  of  words  heard,  auditory- 
verbal  imagery ;  of  words  felt  as  if  they  were  to  be  spoken, 
mo  tor- verbal ;  or  of  words  as  seen  in  print  or  writing.  As 
a  matter  of  fact  verbal  imagery  is  mostly  either  auditory- 
or  motor-verbal.  It  is  too  closely  connected  with  the 
pre-reading  age  for  the  visual  elements  to  be  very  promi- 
nent. There  is  .little  connection  between  the  concrete 
and  the  verbal  imagery  for  most  individuals.  One  may 
be  visual  in  the  memory  of  concrete  objects  while  one's 
verbal  imagery  may  be  either  motor  or  auditory. 

Memory  Types  Usually  Mixed.  —  The  traditional 
treatment  of  imagery  states  or  implies  that  these  types 
are  mutually  exclusive,  that  if  an  individual  has  a  well- 
developed  visual  memory,  he  will  not  have  auditory 
images,  and  vice  versa.  Recent  results  indicate  that 
while  this  may  be  true  for  the  occasional  man,  usually 
for  the  older  men  who  have  become  well  set  in  habits, 
most  individuals  have  more  than  one  sense  represented 
in  imagery.  The  same  individual  may  use  all  the  senses 
in  recall  as  in  perception.  In  that  case  he  will  use  the 
imagery  best  adapted  to  the  event  in  question.  Most 
use  two  or  more  different  forms  of  imagery  and  may  in 
addition  have  a  verbal  memory  of  a  different  sense  from 
that  used  for  concrete  objects.  There  are  also  marked 
differences  in  the  degree  of  clearness  of  the  type  of 
mental  imagery  that  is  dominant.  Of  exclusive  visual- 
isers  some  can  picture  objects  clearly,  some  only  in 
general  or  vague  outline,  and  it  may  happen  that  a  man 
who  uses  visual  imagery  predominantly  may  not  pic- 
ture events  so  clearly  as  another  for  whom  auditory 
imagery  is  dominant. 


164        THE  ESSENTIALS  OF  PSYCHOLOGY 

Imagery  and  Practical  Efficiency.  —  Obviously,  there 
must  be  a  fairly  close  relation  between  the  accomplish- 
ments of  the  individual  and  his  memory  type.  It  would 
foe  very  difficult  to  imagine  a  painter  who  could  not  recall 
colours  and  forms,  or  a  musician  who  had  no  memory 
for  tone.  As  a  matter  of  fact,  most  great  musicians  are 
of  the  auditory  type  and  most  painters  are  visualists. 
In  more  commonplace  affairs  the  memory  type  plays 
.an  important  part.  A  pupil  who  has  little  or  no  visual 
imagery  finds  difficulty  in  spelling.  The  methods  of 
learning,  too,  soon  adapt  themselves  to  the  memory 
type.  It  should  not  be  supposed  from  this  that  powers 
of  observation  are  similarly  restricted.  One  of  the 
visual  type  may  understand  a  lecture  fully  as  well  as 
his  fellow  of  auditory  mind;  as  he  understands,  how- 
ever, he  translates  what  is  said  into  pictures  and  re- 
members these.  Recognition  of  the  voice  may  be  as 
accurate,  also.  The  visual-minded  individual  will  know 
the  voice  of  a  friend  when  he  hears  it  again,  although  he 
may  not  be  able  to  recall  it  at  all.  Apparently,  memory 
types  may  be  trained,  and  undergo  changes  with  age. 
Experiments  in  developing  memory  types  that  were 
originally  weak  have  met  with  some  success,  although 
the  course  of  training  must  be  long.  Imagery  tends  to 
become  less  concrete  and  definite  with  advancing  years, 
particularly  if  the  individual  devotes  himself  to  pursuits 
requiring  abstract  thought.  Galton  found  that  English 
men  of  science  had  very  little  definite  imagery.  Most 
thinking  was  in  verbal  imagery  or  in  other  more  abstract 
forms  of  thought.  It  seems  that  the  general  tendency, 
as  men  deal  more  and  more  with  principles  and  less  and 


RETENTION  AND   ASSOCIATION  1 6$ 

less  with  particulars,  is  toward  a  disappearance  of  de- 
tailed imagery,  and  its  replacement  by  symbols.  The 
objects  are  represented  in  memory  by  imagery  that  has 
less  and  less  resemblance  to  them,  but  which  is  better 
adapted  to  the  needs  of  quick  and  accurate  thought. 

Summary.  —  Our  third  fundamental  mental  fact  is 
that  impressions  received  from  the  senses  are  retained 
in  the  nervous  system  as  dispositions  to  re-excitation. 
They  return  when  some  experience  that  has  been  con- 
nected with  them  precedes  them  in  consciousness.  This 
recall  is  subject  to  the  same  laws  of  selection  that  are 
exhibited  in  attention.  When  these  dispositions  become 
realised,  they  constitute  the  elements  of  memory,  imag- 
ination, and  reason.  They  are  similar  to  the  original 
sensations,  although  much  poorer  in  the  number  of  dis- 
tinguishable qualities.  In  the  representation  of  objects, 
not  all  the  elements  of  the  original  object  need  be  present. 
One  or  more  sense  departments  may  predominate  in  recall 
to  the  exclusion  of  others. 

The  three  general  principles  upon  which  all  explana- 
tion in  psychology  must  rest  have  now  been  outlined. 
The  first  is  that  all  our  knowledge  comes  originally  from 
sensation.  All  of  its  fundamental  qualities  are  deter- 
mined by  the  character  of  the  sense-organs,  together 
with  the  nature  of  the  external  stimuli.  There  are 
some  forty  of  these  simplest  qualities.  These,  by  their 
interaction  and  combination,  give  rise  to  the  complexes 
of  qualities  found  in  the  concrete  objects  of  experience. 
The  second  principle  is  that  the  order  in  which  mental 
processes  of  any  sort  enter  consciousness  and  whether 
any  process  does  or  does  not  enter  consciousness,  depends 


1 66        THE  ESSENTIALS  OF  PSYCHOLOGY 

upon  the  nature  of  the  individual  rather  than  upon  the 
forces  in  the  physical  world.  The  nature  of  the  in- 
dividual that  determines  the  entrance  to  consciousness 
is  itself  derived  from  his  earlier  experience  and  heredity. 
This  fact  of  selection  is  the  deciding  influence,  not  only 
in  perception,  but  also  in  recall,  and  in  the  voluntary 
control  of  action.  The  third  and  last  of  these  principles 
is  that  each  experience  leaves  a  disposition  in  the  nervous 
system  that  tends  to  the  reinstatement  of  that  experience 
on  suitable  occasion.  These  three  principles  recur  to- 
gether again  and  again  in  the  explanation  of  the  concrete 
mental  operation.  Together,  they  suffice  for  the  under- 
standing of  practically  all  mental  processes. 

QUESTIONS 

1.  What   are  centrally  aroused   sensations?    What   are   the 
common  names  for  some  of  the  concrete  processes  which  they 
constitute  ? 

2.  How  are  experiences  retained?    Are  they  retained  as  ideas 
or  as  nervous  effects  ? 

3.  Can  you  see  any  relation  between  the  nervous  basis  of  the 
retention  and  the  nervous  basis  of  habit  ? 

4.  What  is  the  perseveration  tendency? 

5.  How  far  are  the  'laws  of  association'  explanations  and  how 
far  mere  classifications? 

6.  What  is  the  fundamental  neurological  process  in  associa- 
tion? 

7.  How  can  one  explain  association  by  similarity  in  nervous 
terms  ?  association  by  contrast  ? 

8.  What  are  the  'subjective  conditions '  of  associations?    How 
related  to  subjective  conditions  of  attention? 

9.  Give  possible  explanations  of  failure  to  recall  a  well-known 
fact. 


RETENTION  AND   ASSOCIATION  167 

10.   How  does  'primacy'  affect  retention  and  recall? 

ji.  How  do  you  distinguish  between  a  memory  and  a  real 
object  as  you  see  it?  Which  is  centrally,  which  peripherally 
aroused  ? 

EXERCISES 

1.  Trace  the  similarities  and  differences  between  an  after- 
image, a  memory  after-image  or  primary  memory,  and  a  memory 
image.     Look  at  a  bright  object  for  ten  seconds.     Close  the  eyes 
and  describe  or  note  the  after-image.     Take  a  momentary  glance 
at  the  same  object  and  note  the  memory  image  of  the  object  that  is 
obtained.     Compare  it  with  the  after-image  for  clearness  of  outline 
and  quality.     Recall  some  similar  object  that  was  seen  yesterday 
and  compare  it  in  every  respect  with  the  other  two.     How  are  the 
three  processes  related  nervously  ? 

2.  Let  your  mental  stream  flow  at  random  for  half  a  minute. 
Write  out  the  ideas  that  came  to  you  in  the  order  of  their  appear- 
ance.    Can  you  trace  the  order  to  earlier  connections  of  simultane- 
ity or  succession  ?    Are  there  instances  in  which  one  idea  dissolves 
into  another?     Classify  the  associations  in  accordance  with  the 
text.     Are  the  simple  or  the  complex  associations  more  frequent? 

3.  In  the  list  above  mark  the  connections  due  to  primacy,  to 
recency,  to  intensity,  and  to  frequency. 

4.  Speak  a  word  to  an  assistant  with  the  request  to  say  the  first 
word  that  comes  to  mind.     Repeat  for  twenty  words.     Note  the 
sorts  of  connections  as  in  the  preceding  exercise.     How  long  does  it 
take  to  complete  the  series?     Choose  a  series  of  words  that  have 
easy  opposites  and  ask  the  assistant  to  give  the  opposites.    Take 
the  time  as  before.     How  does  it  compare  with  that  obtained  for 
the  first  series?     How  often  does  the  assistant  think  of  a  wrong 
word  before  the  opposite  comes?    How  does  the  second  series 
illustrate  control  of  association  or  recall? 

5.  Recall  the  last  public  lecture  that  you  attended.     Can  you 
see  the  speaker  ?     Can  you  hear  the  words  that  he  speaks  ?     Can 
you  recall  in  any  way  the  peculiarities  of  his  voice?    How?     Can 
you  reproduce  the  pressure  of  the  programme  that  you  held  in 


1 68  THE  ESSENTIALS   OF  PSYCHOLOGY 

your  hands  ?  the  strain  from  an  uncomfortable  position  ?  Do  you 
have  distinct  memories  of  taste  and  smell?  Can  you  grade  the 
clearness  of  the  memories  from  the  different  senses? 

6.  Do  you  project  your  memory  images  in  the  same  direction  as 
your  sense  impressions  ?  For  instance,  do  you  think  of  the  speaker 
in  the  preceding  exercise  as  in  front  of  you,  or  behind,  or  to  the 
right  ?  How  large  do  you  think  the  speaker  to  be  in  your  memory 
projection?  Do  the  objects  have  the  same  colour  and  the  same 
background  as  the  actual  sensations? 

REFERENCES 

ANGELL  :  Psychology,  ch.  vii. 

TITCHENER:  Textbook  of  Psychology,  pp.  374-401. 

PILLSBTJRY  :  Attention,  ch.  vii. 

JAMES  :  Principles  of  Psychology,  vol.  i,  ch.  xix. 

SEASHORE  :  Elementary  Experiments  in  Psychology,  ch.  k. 


CHAPTER  VH 
PERCEPTION 

Perception  Involves  a  Correction  of  Sensations.  — 
So  far  we  have  been  dealing  with  general  principles  and 
the  laws  which  hold  for  all  mental  action.  In  perception 
we  begin  to  discuss  concrete  mental  processes.  We 
perceive  things,  not  sensations  or  images,  although  in 
psychology  we  think  of  things  when  appreciated  as  being 
in  some  way  made  up  of  sensations  and  images.  In  the 
discussion  of  perception  we  must  show  how  the  laws  and 
elements  that  have  been  discussed  in  the  last  three  chap- 
ters combine  and  interact  in  the  attainment  of  a  knowl- 
edge of  the  real  world.  First  we  must  see  that  there  is 
a  real  problem  here.  We  have  become  so  familiar  with 
seeing  things  and  with  hearing  things  that  it  seems  now 
that  objects  in  some  way  walk  over  into  our  consciousness 
with  the  same  characteristics  that  they  have  in  the  out- 
side world.  As  with  any  operation  that  has  been  fre- 
quently repeated,  we  soon  come  to  overlook  the  various 
steps  in  the  procedure,  and  it  is  necessary  to  learn  in 
some  indirect  way  what  is  actually  done.  In  this  in- 
stance it  is  doubtful  if  the  individual  ever  knew  the 
methods  by  which  he  attains  a  knowledge  of  objects. 
That  his  assumption  that  objects  are  like  the  effects 
they  produce  on  the  sense-organ  is  erroneous,  a  simple 
examination  of  the  facts  of  perception  proves  conclu- 
169 


1 70  THE   ESSENTIALS    OF   PSYCHOLOGY 

sively.  The  sensations  that  are  received  are  added  to 
or  changed  to  make  them  correspond  more  exactly  to 
what  from  our  different  earlier  experiences  we  know  they 
must  be.  One  always  corrects  the  shape  of  the  table  top 
as  it  appears  in  perspective.  The  angles  are  right  angles 
as  we  see  them,  although  the  image  must  have  acute  and 
obtuse  angles.  One  also  makes  an  allowance  for  distance 
in  the  size  of  an  object  seen.  The  same  object  is  always 
given  the  same  size  no  matter  how  far  away  it  may 
be,  while  the  image  on  the  retina  diminishes  constantly 
as  the  distance  increases.  Evidently  objects  do  not 
walk  over  into  consciousness  as  one  might  suppose, 
but  the  percept  is  reconstructed  according  to  certain 
laws.  The  problem  of  perception  is  to  determine  these 
laws. 

Perceptions  Involve  Recalled  Elements.  —  The  first 
fact  we  meet  -is  that  perceptions  often  involve  centrally 
aroused  sensations  or  memories,  as  well  as  sensations. 
In  feeling  a  rough  surface  in  the  dark,  one  recalls  how 
surfaces  appear  that  have  given  similar  tactual  sensa- 
tions. If  the  arm  is  moved  with  the  eyes  closed,  one 
ordinarily  pictures  from  memory  the  different  positions 
of  the  arms ;  one  does  not  feel  the  sensations  from  the 
arm  that  tell  of  the  motion.  Similarly,  in  any  percep- 
tion, the  object  is  made  up  in  part  of  memories  and  in 
part  of  sensations.  In  perception  through  any  sense 
the  same  law  holds.  When  a  dog  barks  at  a  distance, 
the  dog  is  pictured  in  its  proper  direction,  —  visual 
memories  are  added  to  the  auditory  sensations.  The 
memory  additions  can  be  actually  discriminated  under 
certain  conditions.  In  Figure  22,  taken  from  Jastrow, 


PERCEPTION  I?I 

the  shadows  alone  are  drawn  but  one  seems  to  see  the 
lines  which  they  suggest.  They  are  a  little  faint,  but 
are  unmistakable  and  can  be  seen  even  under  conditions 
most  favourable  for  observation.  In  most  perceptions 
there  are  similar  additions  from  memory,  although  they 
are  not  always  so  easily  distinguished. 

Perception  of  Objects  as  Real.  —  In  many  cases, 
however,  the  object  that  is  seen  is  not  supplied  by  any 
one  memory,  but  from  a  number  of  earlier  experiences. 
Thus  no  one  has  ever  seen  the  table  top  as  it  presents 
itself  in  perception.  When  seen  from  one  side  it  slants 
in  one  direction,  seen  from  the  opposite  side  it  slants 
in  the  other  di- 
rection.  When 
seen  from  in 
front  the  sides 

Converge   toward     FIG.  22.  —  (From  Jastrow  :  '  Fact  and  Fable  in  Psy- 

the    back,     and  choiogy,'  Fig.  2.) 

even  when  looked  at  from  a  point  directly  above  the 
centre  of  the  top,  the  sides  would  not  be  straight,  as  we 
know  from  the  fact  that  the  retina  is  a  sphere,  not  flat,  and 
from  direct  observation  under  suitable  conditions.  In 
Figure  23,  taken  from  Helmholtz,  if  you  will  look  at  the 
centre  when  it  is  held  only  an  inch  or  so  from  the  eye  all 
the  lines  appear  straight  and  the  angles,  right  angles. 
The  figure  is  drawn  in  such  a  way  that  the  curvatures  are 
just  corrected  by  the  change  in  the  image  that  produces 
a  distortion  of  straight  lines  as  they  are  normally  seen. 
Everything  we  see  on  the  periphery  of  the  retina  is 
distorted  in  the  direction  opposed  to  this.  While  the 
retinal  image  must  always  have  been  distorted  in  some 


.  . 

[/      "N  f~*}   P) 

f~~^  I   ["""  \ 

-  lJ  -  J  J  J        si—/  J      A 


172        THE  ESSENTIALS  OF  PSYCHOLOGY 

way,  the  object  as  we  perceive  it  is  rectangular  and  the 
edges  are  perfectly  straight.  Obviously  factors  other 
than  the  recall  of  some  single  earlier  memory  must  have 
been  effective  in  making  the  sides  straight  and  the 


JIG.  23.  —  To  show  the  distortion  in  the  periphery  of  the  visual  field.  Hold 
the  centre  of  the  figure  at  a  distance  from  the  pupil  equal  to  the  line  below 
and  the  lines  are  all  straight  and  the  angles  right  angles.  (From  Helmholtz.) 

angles  right  angles.  It  is  probable  that  some  of  this 
modification  of  memories  and  sensations  is  due  to  the 
results  of  tests  in  various  actions.  One  has  found  that 
the  table  will  fit  into  square  corners,  and  that  if  one  is 
to  make  a  table  that  has  the  appearance  of  this,  the  ends 


PERCEPTION  173 

and  sides  must  be  straight  and  all  the  angles  right  angles. 
All  the  uses  and  tests  that  have  been  made  harmonise 
with  the  assumption  that  the  table  top  is  a  square, 
and  as  a  result  of  all  of  these  experiences  one  sees  it 
square,  whatever  the  retinal  image  may  be.  The  re- 
sults of  all  of  the  various  experiences  cooperate  in  giving 
the  object  that  is  seen  the  appearance  it  has.  To  put  it 
the  other  way,  the  object  that  is  seen  is  the  one  that  serves 
to  explain  the  different  earlier  experiences ;  it  is  the  one 
that  harmonises  all  of  the  uses  and  observations  we  have 
made  of  it  in  the  past.  By  constant  trial  and  use,  a 
construction  develops  that  proves  true  when  tested  in 
any  way.  This  is  accepted  as  the  real  object  as  opposed 
to  mere  sensations.  Whenever  the  sensation  presents 
itself,  this  developed  object  arises  in  consciousness. 

Not  only  do  constructions  that  have  proved  true  on 
test  replace  the  actual  sensations  that  are  true  under  only 
one  condition  of  perception,  but  sensations  that  on  test 
prove  not  to  have  external  existence  are  overlooked  al- 
together. Probably  many  readers  of  this  book  never  saw 
an  after-image  until  they  read  the  chapter  on  sensation, 
although  every  visual  sensation  has  its  after-image. 
Again  ordinarily  you  do  not  see  the  shadows  cast  on 
the  rods  and  cones  by  the  retinal  blood-vessels,  but  if 
in  the  dark  a  candle  be  held  a  little  to  one  side  of  the  line 
of  vision  and  moved  about,  the  network  of  vessels  will 
be  evident.  These  shadows  are  overlooked  because 
they  have  no  meaning  in  the  world  without.  In  gen- 
eral, perception  is  always  of  real  objects;  sensations 
that  do  not  correspond  to  real  objects  are  always  neg- 
lected. The  character  of  the  percept  is  changed  to 


174        THE  ESSENTIALS  OF  PSYCHOLOGY 

correspond  to  what  has  proved  to  be  the  real  object. 
An  object  in  its  turn  is  real  if  it  will  stand  the  ordinary 
tests,  will  satisfy  the  different  uses  to  which  it  may  be 
put,  and  will  harmonise  with  all  the  related  experiences. 
What  one  sees  is  the  object  which  has  proved  itself 
real  as  a  result  of  the  various  earlier  perceptions  and 
which  stands  the  test  of  all  the  various  trials.  Percep- 
tion is  different  from  sensation  in  three  ways :  (i)  Mem- 
ory images  are  always  added  to  the  sensations  to  com- 
plete them  and  interpret  them.  (2)  The  percept  is 
not  a  mere  sum  of  sensations  and  memories  but  an 
explanation  of  this  and  earlier  experiences  of  the  same 
or  similar  objects,  developed  by  repeated  experiences 
and  tests  of  different  kinds.  This  explanation  or  inter- 
pretation is  frequently  very  little  like  any  single  group 
of  sensations  that  ever  has  been  received  from  the  object. 
(3)  Since  the  percept  satisfies  the  different  uses  to 
which  it  has  been  put,  it  is  regarded  as  real,  while  the 
actual  sensations  may  be  regarded  as  unreal  or  illusory. 
The  Determinants  of  Perception.  —  If  perception  is 
made  up  of  memories  as  well  as  of  sensations,  it  is  evident 
that  the  object  seen  depends  not  only  upon  the  sensations 
that  affect  the  sense-organ,  but  also  upon  memories 
and  the  laws  of  association  and  recall.  Where  the 
right  memories  are  lacking,  there  is  no  possibility  of 
correct  or  complete  perception.  This  is  seen  in  the 
failure  to  understand  or  even  to  hear  all  that  is  said 
in  a  foreign  tongue.  One  could  not  repeat  accurately 
even  a  short  sentence  in  French  if  entirely  unfamiliar 
with  the  language,  and  this  largely  because  the  sounds 
would  not  be  correctly  supplemented.  One  sees  much 


PERCEPTION 


175 


more  in  an  instrument  that  one  already  knows  some- 
thing about.  To  go  back  to  the  beginning,  it  is  probable 
that  the  child  sees  practically  nothing  in  the  world 
because  it  has  nothing  to  bring  to  it  in  the  way  of  earlier 
experiences.  But  as  in  the  case  of  recall  in  general, 
what  is  seen  depends  not  only  upon  having  the  memories, 
but  upon  being  able  to  get  them  back  at  the  right  time. 
There  is  frequently  a  choice  in  the  interpretation  that 
shall  be  put  upon  an  object.  Under  these  circumstances 
what  is  seen  depends  upon  the  setting  of  the  object  or 
the  attitude  at  the 
moment.  Associa- 
tions are  subject  to 
the  same  laws  in 
perception  as  in 
recall  in  general. 
The  drawing  in 
Figure  24  may  be 
seen,  either  as  a 
flight  of  steps  or  as 
a  cornice,  according  as  one  brings  the  right  ideas  to 
bear.  The  figure  from  Jastrow,  Fig.  25,  may  be  seen 
as  a  rabbit's  head  or  as  a  duck's  according  as  one 
thinks  of  one  or  the  other.  The  same  dependence  upon 
attitude  may  be  seen  in  more  usual  perceptions.  If  one 
is  listening  for  footsteps  at  night,  many  sounds  are  likely 
to  be  interpreted  as  footsteps.  As  a  preliminary  state- 
ment it  may  be  asserted  that  any  perception  depends 
upon  (i)  the  presence  of  a  sensation  or  group  of  sensa- 
tions ;  (2)  the  recall  by  these  of  sensations  or  objects 
earlier  experienced;  and  (3)  upon  the  mental  attitude 


FIG.  24. 


176        THE  ESSENTIALS  OF  PSYCHOLOGY 

and  more  general  influences  which  determine  this  recall. 
We  may  proceed  to  the  discussion  of  the  way  these  laws 
act  in  giving  rise  to  the  different  forms  of  perception 
ordinarily  recognised. 


FIG.  25. —  (From  Jastrow,  op.  tit.,  Fig.  19,  p.  295.) 

Perception  of  Space.  —  Two  properties  or  aspects  of 
objects  are  sufficiently  alike  for  all  to  be  treated  irre- 
spective of  the  objects  themselves.  These  are  space  and 
time.  Space  has  been  particularly  thoroughly  investi- 
gated. Following  the  usage  of  geometry,  psychology 
distinguishes  three  phases  of  the  perception  of  space : 
(i)  the  perception  of  position,  (2)  the  perception  of  dis- 
tance on  the  surface  of  the  sense-organ,  and  (3)  per- 
ception of  depth  or  distance  away  from  the  sense-organ. 
Each  of  these  illustrates  the  general  laws  of  perception. 


PERCEPTION   OF   SPACE  177 

The  perception  of  position  on  skin  or  eye  is  so  simple 
and  has  been  made  so  frequently  that  it  is  difficult 
to  distinguish,  directly  or  indirectly,  the  immediate 
conditions  that  give  rise  to  it.  If  one  touches  a  finger 
or  the  cheek,  one  knows  at  once  what  the  point  is  that 
has  been  touched,  but  one  cannot  say  how  it  is  known 
that  it  is  that  point  and  no  other.  That  the  perception 
of  position  involves  physiological  and  psychological 
processes  is  evident  from  the  fact  that  the  accuracy  of 
localisation  varies  from  point  to  point  on  the  body. 
This  may  be  demonstrated  by  two  experiments.  Have 
ypurself  touched  on  the  skin  and  try  to  indicate  the 
point.  You  will  make  a  mistake  of  a  millimetre  or  more 
if  the  point  be  on  the  finger  tip  and  of  several  centimetres 
if  on  the  back  or  thigh.  Or  you  may  have  some  one 
touch  you  with  two  compass  points  and  determine  how 
far  apart  they  must  be  before  you  can  say  that  they  are 
two  rather  than  one.  This  distance  is  the  *  limen  of 
twoness.'  On  the  finger  tip  it  is  about  i  mm.,  on  the 
back,  40-60  mm.  Similarly  for  the  retina,  one  finds  a 
'  limen  of  twoness  '  at  the  fovea  of  .oo4~.oo6  mm.  or 
about  the  distance  between  the  cones.  The  limen 
increases  very  rapidly  with  the  distance  from  the  fovea. 
The  'Local  Sign.'  —  To  bring  these  facts  under  our 
explanation  of  perception,  it  is  necessary  to  find,  first, 
some  old  experiences  that  were  suggested  when  the 
point  was  touched,  and  second,  the  peculiar  quality 
of  the  point  that  suggests  them.  Various  theories  have 
been  held  concerning  the  nature  of  both.  One  of  the 
oldest  is  that  there  is  a  sign  of  position,  the  *  local  sign/ 
that  is  different  for  each  point  touched  and  for  each 


178  THE  ESSENTIALS   OF  PSYCHOLOGY 

point  of  the  retina  stimulated,  and  that  this  '  local  sign  * 
suggests  the  position.  No  one  has  accurately  described 
the  '  local  sign,'  however,  and  one  cannot  discover  it 
when  one  seeks  it.  Another  theory  is  that  stimulation 
of  each  point  on  the  skin  tends  to  call  out  some  reflex 
movement  and  that  this  reflex  is  different  for  each  point. 
There  is,  on  this  theory,  either  a  movement  or  a  tendency 
to  movement  which  is  different  for  each  point  of  the  skin 
or  eye.  This  theory  is  partly  satisfactory;  the  main 
objection  is  that  one  can  recognise  position  more  accu- 
rately than  one  can  touch  points  on  the  skin,  and  that 
the  eye  is  constantly  moving  over  distances  greater  than 
the  least  appreciable  differences  in  position.  Another 
suggestion  for  the  perception  of  position  on  the  skin  is 
that  the  contact  recalls  a  visual  picture  of  the  point. 
This  is  the  only  suggestion  that  can  be  confirmed  by 
actual  observation.  The  most  that  can  be  said  is  that 
perception  of  position  is  due  to  some  peculiar  quality 
or  motor  connection  attaching  to  each  point  on  the 
skin  or  retina.  It  is  likely  that  position  itself  is  an 
idea  so  frequently  used  that  its  nature  has  become 
very  complex,  and  the  elements  are  no  longer  analysed 
from  the  mass.  It  is  made  up  partly  of  movements  or 
tendencies  to  movement  and  partly  of  ideas  derived 
from  sight  or  touch  as  the  case  may  be,  but  also  involving 
a  number  of  other  elements.  This  notion  of  position, 
whatever  its  nature,  explains  all  the  various  experi- 
ences and  responds  satisfactorily  to  all  tests.  With 
use,  the  completed  notion  has  come  to  replace  the  dif- 
ferent elements  so  entirely  that  they  are  lost  in  it,  and 
cannot  now  be  analysed  from  it.  The  stimulation  of  any 


PERCEPTION   OF   SPACE  179 

point  on  skin  or  retina  calls  out  the  corresponding  notion 
of  position,  and  that  is  all  that  can  be  said  with  certainty. 
Perception  of  Distance.  —  The  perception  of  distance 
on  the  surface  of  skin  or  retina  is  dependent  upon  the 
suggestion  of  a  similar  complex  that  has  been  no  more 
completely  analysed.  The  one  element  that  has  been 
discovered  in  the  notion  of  distance  is  movement.  Sev- 
eral illusions  indicate  that  one  appreciates  distance  on 
the  retina  by  moving  the  eyes  from  point  to  point. 
Thus,  vertical  distances  are  overestimated  as  compared 
with  horizontal  distances,  because  the  adjustment  of 
the  eye  muscles  makes  vertical  movements  of  the  eyes 
more  difficult  than  horizontal  ones.  Distances  on  the 
skin  also  tend  to  be  translated  into  movement,  and  the 
mistakes  made  show  dependence  upon  movement.  In 
addition,  it  is  probable  that  distances  on  the  skin  are 
translated  into  visual  distance  for  interpretation,  and 
that  visual  distances  may  more  rarely  be  translated  into 
distances  on  the  skin.  That  there  is  usually  reference 
from  one  sense  to  another  is  shown  by  the  fact  that 
where  two  systems  of  distance  are  independent  and 
not  corrected  by  comparison,  large  mistakes  are  apt  to 
be  made.  This  explains  the  large  size  that  cavities  in  the 
teeth  seem  to  have  when  felt  by  the  tongue,  as  compared 
with  their  size  when  seen  in  the  dentist's  mirror.  Space 
as  perceived  by  the  tongue  is  seldom  corrected  by  visual 
space,  while  other  tactual  distances  are  constantly  sub- 
ject to  that  correction.  Distance,  then,  is  a  complex  of 
numerous  factors  that  have  been  lost  in  a  more  general 
notion.  This  notion  is  aroused  whenever  one  estimates 
distance  by  the  eye,  on  the  skin,  or  by  the  movement  of 


l8o        THE  ESSENTIALS  OF  PSYCHOLOGY 

the  members.  What  it  is  in  itself  one  can  no  longer  say, 
if  one  ever  was  able  to  analyse  all  of  the  experiences  that 
have  gone  to  make  it  up  or  that  have  served  to  develop  it. 

Perception  of  the  Third  Dimension.  —  The  perception 
of  the  distance  of  objects  from  the  eye  illustrates  all  of 
the  laws  of  perception  even  more  clearly  than  the  simpler 
forms  of  space  perception.  The  striking  fact  in  connec- 
tion with  perception  of  this  third  dimension  is  that,  while 
the  rays  of  light  affect  the  retina  only,  the  objects  that 
reflect  them  seem  to  be  some  distance  away  from  the 
eye.  Evidently  distance  cannot  depend  upon  how  the 
retina  is  stimulated,  because  a  point  of  light  affects  the 
retina  in  the  same  way  whether  the  source  be  two  feet 
away  or  as  remote  as  a  fixed  star.  That  the  actual  dis- 
tance makes  little  or  no  difference  can  also  be  demon- 
strated by  the  fact  that  objects  within  the  eye  and  even 
within  the  retina,  when  seen  at  all,  seem  to  be  in  the  outer 
world,  and  at  a  distance  from  the  eye  that  depends  upon 
the  adjustment  of  the  eyes  at  the  time.  So,  if  one  lie 
upon  the  back  on  a  summer  day  gazing  upward,  one  will 
notice  little  bright  specks  rushing  over  the  sky.  These 
are  the  blood  corpuscles  darting  through  the  blood-vessels 
in  the  retina,  but  when  the  eye  is  fixed  upon  the  sky  they 
appear  to  be  far  away.  The  problem  of  the  perception 
of  distance  is  one  of  determining  what  in  the  character  of 
the  excitation  calls  out  the  idea  of  distance,  and  what  the 
nature  of  that  idea  is. 

The  Physiological  Factors.  —  The  factors  which  serve 
to  suggest  the  distance  have  been  pretty  fully  made  out. 
They  may  be  classified  into  eight  groups,  three  physio- 
logical and  five  psychological.  The  physiological  factors 


PERCEPTION  OF  SPACE  l8l 

are  related  directly  to  the  adjustment  of  the  eyes.  With 
one  eye  only,  the  most  important  element  is  the  change 
in  the  contraction  of  the  ciliary  muscle  that  focusses 
the  eye  for  different  distances.  If  one  looks  at  a  dis- 
tant object,  the  lens  is  flat  and  the  muscle  of  accommoda- 
tion is  relaxed ;  if  one  looks  at  a  near  object,  the  lens 
is  rounded  and  the  muscle  contracted.  One  may  feel 
the  change  in  strain  as  one  looks  from  a  remote  to  a 
near  object.  This  strain  of  accommodation  gives 
an  idea  of  the  distance  of  the  object.  Slight  strain 
means  distance,  increased  strain  means  nearness.  The 
estimation  of  distance  by  one  eye  is  much  less  accurate 
than  with  two  eyes,  as  can  be  shown  by  asking  one  to  put 
his  ringer  through  a  ring  held  sidewise.  With  one  eye 
large  mistakes  will  be  made,  while  with  two  eyes  one  can 
put  the  finger  through  each  time.  Muscular  strain  is  also 
a  factor  in  binocular  perception  of  distance.  When 
one  looks  at  a  distant  object,  the  eyes  are  parallel;  as 
one  looks  at  nearer  objects,  the  eyes  converge,  and  the 
nearer  the  object,  the  greater  the  convergence.  This 
can  be  seen  directly  in  another's  eyes.  When  he  looks 
at  a  distant  object,  the  white  shows  about  equally  on 
each  side ;  as  he  looks  at  an  object  only  a  foot  away, 
considerably  more  white  will  show  on  the  outside  than  on 
the  inside  of  the  eyes.  This  adjustment  is  made  known 
to  the  observer  by  the  strain  sensations  from  the  muscles 
which  turn  the  eyes.  These  vary  with  the  distance 
of  the  object.  It  is  to  be  emphasised  that  none  of  these 
strain  sensations  are  noticed  for  themselves.  They  are 
overlooked  in  the  interpreting,  and  one  appreciates  the 
distance  alone,  not  the  strains  that  suggest  it. 


182 


THE  ESSENTIALS  OF  PSYCHOLOGY 


Double  Images.  —  One  of  the  most  important  ele- 
ments in  the  perception  of  distance  is  the  different 
appearance  that  objects  present  to  each  eye.    If  one 
A 


FIG.  26.  —  To  illustrate  perception  of  depth  through  double  images.  F  is  the 
fixation  point,  A  and  B  farther  and  nearer  points.  Both  nearer  and  farther 
points  are  projected  upon  the  plane  through  the  fixation  point  and  so  are 
seen  double;  B  as  if  it  were  at  both  B'  and  B" ' ;  A  as  if  it  were  both  at  A' 
and  A". 

will  hold  any  object  before  the  eyes  and  look  at  it  first 
with  one  eye,  then  with  the  other,  it  will  be  noticed  that 
one  eye  sees  more  of  one  side,  the  other  more  of  the  other. 


PERCEPTION   OF   SPACE  183 

If  both  eyes  are  opened,  it  is  possible  to  distinguish  in 
the  common  view  the  contributions  of  each  eye.  The 
difference  in  the  pictures  decreases  as  the  object  moves 
farther  away.  The  distance  of  the  object  is  estimated 
from  the  amount  of  difference  in  the  impressions  on  the 
two  retinas.  Similarly  one  can  distinguish  the  dif- 
ference in  distance  of  objects  by  the  degree  of  double- 
ness  of  the  image  of  the  one  not  directly  converged  upon. 
If  one  will  hold  two  pencils  at  different  distances  from  the 
eyes,  it  will  be  noticed  that  the  pencil  not  fixated  is 
double,  whether  it  be  nearer  or  farther  from  the  eye. 
The  distance  between  them  is  estimated  directly  in 
terms  of  the  degree  of  doubleness  of  the  images.  As  a 
result  of  these  double  images,  every  object  in  the  field  of 
vision  gives  an  immediate  sign  of  its  distance.  It  is 
largely  due  to  these  double  images  that  the  whole  field 
of  vision  is  seen  at  any  moment  to  have  depth.  The 
stereoscope  makes  application  of  this  principle  of  double 
images  to  give  the  appearance  of  depth  to  pictures. 
The  stereoscope  slide  has  two  photographs  taken  from 
slightly  different  positions.  When  the  two  pictures  are 
combined,  the  result  is  a  series  of  double  images  similar 
to  those  that  would  have  been  produced  had  the  observer 
been  standing  where  the  photographs  were  taken. 
The  difference  in  the  pictures  may  be  seen  if  one  will 
compare  the  position  of  the  same  object  in  each.  An 
object  in  the  foreground  will  be  seen  nearer  the  right  edge 
of  the  view  in  the  left  picture,  and  farther  from  it  in  the 
right  picture ;  in  the  background,  the  relation  is  reversed. 
These  double  images  again  are  not  noticed  for  themselves, 
either  in  perceiving  actual  distances  or  in  the  stereoscope. 


184        THE  ESSENTIALS  OF  PSYCHOLOGY 

They  are  overlooked  in  favour  of  the  distances  they 
suggest. 

Psychological  Factors  in  Depth  Perception.  —  The 
psychological  signs  of  distance  are  found  in  certain 
qualities  of  images  which  vary  with  the  distance  of  their 
objects.  The  most  important  of  these  is  the  variation  in 
size  of  the  retinal  image  of  objects  as  they  change  their 
distance.  This  is  the  element  that  the  artist  makes  use 
of  hi  perspective  drawing.  He  draws  the  more  distant 
objects  smaller  than  the  nearer,  and  we  interpret  that  to 
mean  that  they  are  distant.  A  second  sign  of  distance 
is  the  haze  and  changed  colour  that  come  with  distance. 
Distant  objects  are  hazy,  indistinct,  and  blue  in  colour, 
while  near  objects  are  clear  and  have  their  own  colours. 
The  changed  colour  and  haze  depend  upon  the  amount 
of  air  intervening.  In  a  very  clear,  dry  air,  estimates  of 
distance  are  subject  to  large  mistakes  on  the  part  of  one 
who  comes  from  a  lower  altitude  and  denser  atmosphere. 
Distant  objects  show  but  little  haze  or  change  of  colour, 
and  in  consequence  are  regarded  as  much  nearer  than 
they  actually  are.  A  third  factor  of  some  importance  in 
giving  an  idea  of  the  distance  of  objects  is  their  rate  of 
movement,  either  when  they  themselves  move  or  when 
the  head  or  body  of  the  observer  is  moved.  If  the  usual 
rate  of  motion  of  an  object  is  known,  its  apparent  rate 
indicates  its  distance.  Far  objects  seem  to  move 
more  slowly,  near  ones  more  rapidly.  A  distant  railway 
train  seems  to  crawl  across  the  landscape,  while  the  near 
one  rushes  past.  As  one  moves  the  head  with  the  eyes 
fixed  upon  the  horizon,  near  objects  are  displaced  con- 
siderably, distant  ones  very  slightly  or  not  at  all.  If  one 


PERCEPTION   OF   SPACE  185: 

is  looking  at  a  near  object  and  moves  the  head,  objects- 
far  from  the  point  of  fixation  move  more,  those  near  it 
less.  One  may  measure  the  distance  of  the  object  by  the 
rate  of  motion.  A  fourth,  very  simple  sign  of  relative 
distance  is  superposition.  Objects  that  hide  parts  of 
other  objects  are  evidently  nearer  than  the  objects 
covered.  Finally,  shadows  furnish  a  means  of  estimating 
the  relative  distance  of  parts  of  the  same  object.  Bright 
parts  of  the  surface  are  ordinarily  nearer,  shaded  parts 
more  distant.  The  interpretation  depends  largely  upon 
the  way  the  light  is  falling,  but  with  any  illumination 
lights  and  shadows  give  a  means  of  estimating  the  dis- 
tance of  the  parts.  These  five  characteristics  of  the 
retinal  image  combine  with  the  three  factors  mentioned 
above  to  produce  our  notion  of  the  distance  of  seen 
objects.  The  idea  of  distance  depends  upon  all  taken 
together. 

Theories  of  Depth  Perception.  —  If  the  suggestion 
for  the  distance  is  found  in  one  or  more  of  these  factors, 
the  question  at  once  arises  what  the  idea  of  distance  is 
in  itself.  One  of  the  early  theories  and  one  that  still 
has  many  advocates  is  that  the  various  signs  of  distance 
serve  to  recall  memories  of  earlier  movements  which 
were  necessary  to  reach  the  object.  Movement,  no 
doubt,  contributes  a  large  share  to  the  general  idea. 
It  is  certain  that  other  elements  enter.  Estimates  in 
terms  of  movement  alone  are  more  inaccurate  than 
those  in  terms  of  vision  alone.  One,  for  example,  has 
no  accurate  idea  of  the  distance  walked  through  in  the 
dark,  and  walking  in  the  dark,  one  frequently  tries  to 
think  how  great  the  distance  would  look.  Certainly 


1 86  THE  ESSEiNilALS   OF   PSYCHOLOGY 

the  visual  estimate  of  a  distance  is  ordinarily  more 
accurate  than  the  purely  motor  estimate.  It  is  probable 
that  the  idea  of  distance  is  complex,  made  up  of  a  great 
many  particular  experiences.  In  this,  it  is  like  the  idea 
of  position  or  of  distance  on  the  surface  of  the  sense- 
organ.  What  elements  have  contributed  to  the  total 
effect  cannot  now  be  determined  accurately.  But  to 
movement  must  be  added  the  appearance  of  the  dis- 
tances, when  viewed  from  the  side  and  from  other  angles, 
and  all  the  various  activities  that  are  furthered  and 
hindered  by  distance.  Whatever  this  complex  idea 
may  be,  it  is  at  once  suggested  by  the  strain  sensations, 
by  double  images,  and  the  various  characteristics  of 
the  image  that  constitute  the  psychological  signs  of 
depth.  Each  of  these  primary  space  ideas  has  special 
stimuli  that  suggest  it,  and  is  itself  a  complex  idea  that 
is  like  no  single  experience,  but  is  derived  from  and 
explains  many  experiences.  Space,  as  a  whole,  is 
only  another  general  idea  of  the  same  kind  and  origin 
that  unites  and  explains  the  several  less  general  spatial 
ideas  and  which  is  related  to  each  of  them,  or  combined 
from  them. 

Perception  of  Motion.  —  A  second  form  of  perception 
related  to  the  perception  of  space  and  common  to  all 
objects  is  the  perception  of  motion,  particularly  per- 
ception of  motion  by  the  eye.  We  may  distinguish 
two  ways  of  recognising  motion.  In  one,  we  know 
merely  that  an  object  has  moved;  in  the  other,  the 
object  is  seen  to  move.  The  first  is  illustrated  by  the 
second  hand  and  the  second  by  the  minute  hand  of  the 
watch;  one  can  be  seen  to  move,  the  other  we  know 


PERCEPTION   OF   MOVEMENT  187 

has  moved  only  because  it  changes  its  position  between 
observations.  The  former  alone  requires  explanation. 
Apparently  perception  of  motion  depends  upon-  the 
after-images  left  on  the  retina  by  the  moving  object. 
If  the  hand  is  moved  across  the  field  of  vision,  it  will  be 
noticed  that  there  is  a  streak  behind  it  that  persists  for 
a  brief  time.  The  motion  is  perceived  on  the  basis  of 
this  image.  The  direction  of  the  motion  can  be  deter- 
mined from  the  fact  that  the  image  is  most  clear  near 
where  the  object  was  last  seen.  We  ascribe  motion  to 
an  object  in  the  moving  picture  because  the  pictures 
of  the  object  in  different  positions  combine  to  give  an 
almost  continuous  streak  of  after-image  behind  the  object 
and  this  is  practically  identical  with  the  effect  produced 
by  the  real  motion  of  the  object.  Motion  of  the  eye 
shows  itself  by  after-images  of  all  stationary  objects. 
Where  both  eye  and  object  are  in  motion,  the  motion 
of  each  must  be  inferred  from  the  various  after  effects. 
The  interpretation  in  each  case  is  not  explicit.  As  in 
most  perceptions,  the  result  alone  is  evident ;  the  occa- 
sion for  the  perception  is  overlooked.  In  many  cases 
movement  is  ascribed  to  one  object  or  another  on  the 
basis  of  probability.  In  this  a  mistake  is  often  made. 
For  example,  when  one  is  sitting  in  a  car  in  a  station 
and  a  train  on  the  next  track  starts,  one  is  very  likely 
to  believe  that  one's  own  car  has  started.  This  is 
because  one  expects  the  car  to  start,  and  also  because 
one  is  not  accustomed  to  seeing  objects  move  which  are 
as  large  as  the  side  of  the  car.  The  retinal  image  is 
ambiguous,  and  motion  is  ascribed  to  the  object  which 
seems  most  likely  to  move. 


l88  THE  ESSENTIALS   OF  PSYCHOLOGY 

'  The  Perception  of  Space  by  the  Ears.  —  Two  problems 
must  be  considered  in  relation  to  the  auditory  perception 
of  space,  the  appreciation  of  the  distance  from  which  the 
sound  conies,  and  its  direction.  In  both  cases  the  ref- 
erence is  to  sight.  When  one  hears  a  sound,  one  at  once 
gives  it  a  place  in  the  visual  field.  The  problem  in  each 
case  is  to  determine  the  characteristics  of  the  sound  that 
suggest  one  distance  or  one  direction  rather  than  another. 
The  distance  to  which  a  sound  is  referred  depends  very 
largely  upon  the  intensity  of  the  sound,  provided  the 
actual  intensity  is  known.  The  barking  of  a  dog  is  ap- 
preciated as  near  or  far  according  to  its  intensity  as  com- 
pared with  the  intensity  of  the  sound  when  the  dog  is 
barking  near  at  hand.  Allowance  is  made  for  the  bark  of 
different  kinds  of  dogs  on  the  basis  of  the  quality  of  the 
bark.  Where  the  nature  of  a  sound  is  misinterpreted, 
the  distance  is  wrongly  estimated.  The  buzzing  of  a  fly 
very  near  is  occasionally  mistaken  for  some  strange,  loud 
noise  at  a  distance,  and  similar  mistakes  in  judging  dis- 
tances are  rather  frequent.  The  direction  of  the  sound 
seems  to  be  appreciated  by  the  difference  in  the  intensity 
or  quality  of  a  sound  as  it  affects  the  two  ears.  A  sound 
to  the  right  affects  the  right  ear  more  strongly,  a  sound 
to  the  left  stimulates  the  left  more  intensely.  The  rela- 
tive differences  serve  to  indicate  the  direction  of  the 
sound.  In  the  median  plane,  the  plane  midway  between 
the  two  ears,  the  effect  upon  both  ears  is  the  same,  and 
in  consequence  in  this  plane  it  is  very  difficult  to  say 
where  a  tone  is.  A  pure  tone  directly  in  front  may  be 
referred  to  a  point  directly  behind,  or  to  any  other  part 
of  this  plane.  While  the  different  intensities  of  the  tone 


AUDITORY  PERCEPTION   OF   SPACE  189 

as  they  present  themselves  to  the  two  ears  seem  to  be  the 
important  element  in  the  determination  of  the  direction 
of  the  pure  tones,  noises  and  complex  tones  apparently 
undergo  some  slight  change  in  their  quality  with  change  in 
direction,  which  indicates  position.  This  change  in  qual- 
ity is  due  to  factors  that  have  not  been  altogether  deter- 
mined, but  it  seems  probable  that  it  is  in  part  the  result 
of  the  reenf orcement  of  different  components  of  the  com- 
plex as  the  sound  comes  to  the  ear  from  different  directions. 
The  Space  of  the  Blind.  —  For  the  blind,  the  auditory 
perception  of  space  is  much  more  important  than  for 
the  seeing  individual.  Not  only  are  they  more  accurate 
in  all  of  their  localisations  of  sound,  but  they  use  sound 
to  obtain  an  idea  of  the  space  in  which  they  are  walk- 
ing, and  of  the  distance  of  obstacles.  The  echo  of  the 
footsteps  varies  with  the  size  and  shape  of  the  room, 
and  the  time  between  the  echo  and  the  original  sound 
increases  with  the  distance  of  a  wall  or  other  obstacle. 
Even  when  the  echo  is  not  noticed,  it  affects  the  quality 
of  the  tone.  The  blind  have  learned  to  connect  this 
quality  of  the  tone  with  the  different  distances  of  objects, 
and  guide  their  movements  accordingly.  When  the 
boys  in  a  blind  asylum  were  provided  with  felt  slippers 
in  place  of  their  heavy-soled  shoes,  they  could  not  avoid 
obstacles  with  their  usual  skill.  The  footsteps  were 
noiseless,  and  they  were  deprived  of  their  most  impor- 
tant means  of  appreciating  objects  at  a  distance.  It  is 
said  that  the  blind  ordinarily  refer  their  larger  spaces 
to  auditory  qualities  as  we  refer  them  to  vision.  In  all 
respects  perception  of  space  by  the  ear  follows  the  same 
law  as  perception  by  the  eye  or  skin. 


IQO        THE  ESSENTIALS  OF  PSYCHOLOGY 

Perception  of  Time.  —  Much  less  is  known  definitely 
of  the  perception  of  time  than  of  the  perception  of 
space.  Time  is  much  simpler  than  space  and  has 
fewer  components.  The  statement  is  often  made  that 
time  has  but  one  dimension,  while  space  has  three.  The 
idea  of  time  reduces  to  before  and  after,  together  with  the 
notion  of  different  points  in  the  past.  The  most  essen- 
tial part  of  the  idea  is  change,  and  the  occasion  for  the 
appreciation  of  time  is  also  change  of  some  sort.  Rhyth- 
mic changes  in  nature,  the  movements  of  the  heavenly 
bodies  or  of  pendulums,  give  the  scientific  means  for  the 
measurement  of  time.  Psychological  theories  look  to 
changes  in  the  body  for  the  explanation  of  our  apprecia- 
tion of  time,  of  which  two  forms  must  be  distinguished. 
The  one  applies  to  intervals  of  less  than  four  seconds  in 
length,  the  other  to  longer  periods.  Shorter  periods 
ordinarily  are  referred  to  changes  in  strains,  particularly 
the  strain  that  accompanies  expectation,  and  to  rhyth- 
mic vital  processes  such  as  .breathing.  One  compares 
short  periods  of  time  on  the  basis  of  the  relative  strains 
of  expectation.  The  strains  commence  at  the  begin- 
ning of  the  first  interval  and  increase  in  intensity  until 
the  end.  They  begin  again  with  the  second  interval, 
and  when  they  have  reached  the  same  intensity  as  at 
the  end  of  the  first  interval,  it  is  said  that  the  second 
is  equal  to  the  first.  These  periods  of  expectation 
do  not  ordinarily  last  more  than  three  or  four  seconds 
without  relaxation,  and  even  at  three  seconds  become 
very  unpleasant.  This  is  evident  to  any  one  who  has 
watched  the  movement  of  a  clock  with  a  slow  torsion 
pendulum  or  any  similar  slow  rhythmic  movement.  The 


PERCEPTION   OF   TIME  IQI 

strain  of  waiting  for  the  turn  becomes  unendurable  after 
a  short  period. 

Periods  longer  than  three  or  four  seconds  are  estimated 
in  terms  of  the  events  that  fill  them.  Intervals  in  which 
much  happens  seem  long,  while  those  which  have  few 
incidents  or  are  filled  with  the  monotony  of  routine  acts 
seem  short.  A  month  of  the  ordinary  life  seems  no  longer 
than  a  week  of  travel.  This  law  of  dependence  upon  the 
number  of  events,  holds  primarily  of  time  when  consid- 
ered in  retrospect.  When  the  time  is  passing,  the  greater 
the  number  of  events,  the  shorter  seems  the  time ;  while 
empty  time  seems  very  long.  The  difference  probably 
is  due  to  the  different  ways  of  measuring  time.  While 
one  is  merely  waiting  or  is  bored,  one  is  constantly 
aware  of  the  strain  sensations  that  accompany  expecta- 
tion. In  other  words,  empty  time  seems  long  as  one  lives 
it  through,  but  when  one  looks  back  upon  it  afterward, 
no  events  stand  out  and  the  time  appears  short.  Time 
filled  with  the  ordinary  routine  seems  short  both  in  pass- 
ing and  in  retrospect.  One  is  too  much  interested  to 
notice  the  strains  that  mark  the  passage  of  time  or  else 
the  strains  do  not  get  a  chance  to  reach  any  marked  in- 
tensity, because  events  succeed  each  other  so  closely,  and 
there  is  nothing  to  stand  out  prominently  in  memory. 
The  apparent  decrease  in  the  length  of  the  years  with 
increasing  age  is  an  expression  of  this  law.  In  early  life, 
every  event  is  new  and  seems  important ;  as  one  grows 
older,  less  and  less  attention  is  given  to  the  routine  of  life, 
and  in  consequence  the  days  and  weeks  seem  less  full. 
Strain  sensations  or  the  events  that  fill  an  interval 
furnish  a  basis  for  the  perception  of  time.  The  idea 


192  THE  ESSENTIALS   OF   PSYCHOLOGY 

which  they  suggest  is  a  complex  of  experiences,  based 
primarily  upon  change,  but  involving  many  experiences 
of  motion,  and  even  of  space,  that  have  slowly  combined 
with  them  in  a  consistent,  unitary  whole.  So  far  as 
the  idea  can  be  analysed,  it  is  on  the  same  level  as  the 
idea  of  space. 

Reading  as  an  Illustration  of  Perception.  —  The  per- 
ception of  particular  objects  illustrates  the  same  three 
laws  as  these  more  general  characteristics  of  all  objects. 
One  of  the  best  illustrations  of  the  perception  of  par- 
ticular things  is  to  be  found  in  reading.  Reading  seems 
to  be  a  process  of  taking  words  directly  from  the  page 
to  consciousness.  Investigation  of  the  reading  process 
under  various  conditions  has  demonstrated,  however, 
that  one  does  not  actually  see  all  the  letters  or  words 
that  are  read,  but  receives  only  suggestions  of  the  words, 
and  constructs  or  recalls  them  on  the  basis  of  these  sug- 
gestions. In  the  ordinary  connected  reading  the  eye 
does  not  run  slowly  and  regularly  across  the  line  as  is 
usually  supposed,  but  moves  by  jumps  and  all  reading 
is  done  during  a  few  pauses.  The  number  of  these 
pauses  is  greater  with  less  familiar  material  than  with 
more  familiar ;  there  will  be  from  three  to  six  or  more 
in  the  average  length  of  line.  The  amount  of  material 
read  at  each  pause  is  greater  than  can  be  attended  to  at 
a  single  glance.  One  must  supply  the  rest.  That 
misprints  are  frequently  overlooked  is  also  an  indica- 
tion that  one  receives  but  little  from  the  page,  and  adds 
much  from  memory. 

Three  forms  of  reading  may  be  distinguished ;  these 
differ  in  the  sensations  that  suggest  the  matter  read, 


READING  IQ3 

and  in  the  material  brought  out  to  supplement  the 
sensations.  In  one  we  read  letters ;  in  the  second 
we  read  words ;  and  in  the  third  we  read  for  sense,  and 
neglect  both  letters  and  words.  These  three  are  fre- 
quently combined  or  mixed  in  practice.  When  reading 
the  letters,  as  in  proof-reading,  or  in  reading  separate 
words,  one  usually  sees  only  part  of  the  word,  and  fills 
out  the  letters  seen  by  associates.  Thus  if  '  t '  is  seen, 
one  tends  to  supplement  by  '  h,'  and  '  1 '  is  supplemented 
by  '  y,'  or  other  frequent  associates ;  which  of  these 
associates  it  is  will  depend  upon  the  environment  or 
setting  of  the  letter.  If  the  letter  '  1 '  is  near  the  end  of 
the  word,  it  will  be  supplemented  by  *  y/  while  some 
'other  supplement  would  be  more  likely  at  the  beginning. 
The  other  letters  that  have  been  read  will  also  aid  in 
determining  what  shall  be  seen.  Even  more  general 
contexts  will  have  a  part  in  the  process.  If  one  is  read- 
ing German  words,  one  sort  of  associates  will  predomi- 
nate ;  if  French,  another  sort.  Often  the  word  is  read 
from  its  general  form,  and  the  letters  known  to  compose 
the  word  are  supplied  later.  One  may  at  a  second  glance 
look  to  see  if  the  letter  suspected  is  actually  present,  and 
in  the  right  place.  Even  in  reading  for  letters,  associa- 
tion plays  a  considerable  part ;  the  operation  is  not  one 
of  seeing'  alone. 

Reading  Words  and  Reading  for  the  Sense.  —  The 
associative  processes  have  a  more  important  role  in 
reading  words,  whether  in  connected  discourse  or  singly. 
Here,  what  is  seen  clearly  is  the  form  of  the  word  with 
a  few  letters,  and  these  serve  to  call  up  the  whole  word. 
That  one  usually  reads  words  rather  than  series  of  let- 
o 


194        THE  ESSENTIALS  OF  PSYCHOLOGY 

ters  is  indicated  by  the  fact  that  one  can  read  short 
words  more  quickly  than  single  letters.  The  word 
form,  with  or  without  the  initial  letters,  suggests  the 
word  by  the  laws  of  association,  but  the  associates  are 
controlled  by  the  context  and  setting.  A  form  that 
in  one  connection  suggests  '  there  '  will  in  another  set- 
ting suggest  '  these '  just  as  certainly  and  quickly. 
One  selects  the  word  that  makes  sense  in  the  particular 
context,  and,  if  one  mistakes  the  context,  may  supply  a 
word  that  is  not  present,  or  change  the  word  that  is 
seen  to  another  which  fits  the  context.  The  more 
usual  form  of  reading,  however,  is  neither  of  letters  nor 
of  words,  but  of  ideas.  As  one  reads  one  sees  in  the 
mind's  eye  the  scenes  that  the  author  describes;  the 
words  are  overlooked  or  neglected.  This  reading  for 
sense  or  for  meaning  follows  the  same  laws  as  other  forms 
of  reading.  The  visual  impressions  have  been  connected 
with  ideas,  and  selection  is  made  from  the  ideas  in  accord- 
ance with  the  context,  with  what  has  been  read,  and  with 
the  expectation  of  what  the  author  intends  to  say.  The 
fact  that  the  same  word  may  have  different  meanings  in 
different  contexts  without  any  interference  of  one  mean- 
ing with  the  other  is  an  illustration,  at  once  of  the 
dominance  of  the  idea,  and  of  the  importance  of  the 
context  in  selecting  the  idea.  '  Lead  '  is  a  verb  in  one 
context  and  a  noun  in  another,  but  one  never  thinks  of 
the  noun  when  the  verb  is  intended.  The  idea  that  is 
suggested  is  entirely  different  in  the  two  contexts,  and 
the  idea  alone  is  important.  It  is  because  one  is  so 
much  more  concerned  with  the  idea  than  with  the 
letters  or  words,  that  one  so  seldom  distinguishes  be- 


READING  AS   PERCEPTION  195 

tween  what  is  actually  received  from  sensation  and 
what  is  added  to  interpret  the  sensations.  One  is 
intent  upon  knowing  what  the  author  is  saying,  not 
how  one  knows  it;  the  ideas  are  appreciated,  not  the 
process  of  receiving  them. 

As  this  page  is  read,  the  eyes  dart  from  point  to  point 
on  each  line,  making  perhaps  five  pauses  to  take  in  the 
general  form  of  the  words  and  an  occasional  letter. 
These  sensations  suggest  familiar  words  or  familiar  ideas, 
and  the  suggestions  are  controlled  by  the  context  and 
the  appreciation  of  what  is  to  be  discussed.  As  a 
result,  you  construct  for  yourself  the  ideas  that  I  have 
in  mind  as  I  write.  You  are  aware  of  the  ideas ;  it  is 
only  when  some  new  word  is  introduced,  or  the  state- 
ments are  not  clear,  that  you  become  aware  of  the 
words.  All  other  perceptions  follow  these  same  laws. 
In  listening  to  spoken  words,  you  appreciate  the  ideas, 
not  the  sounds.  Sometimes  when  one  is  listening  to  a 
language  more  familiar  in  print  than  in  speech,  one 
translates  the  sounds  into  visual  pictures  before  one 
understands,  just  as  in  the  early  stages  of  reading  one 
may  translate  the  words  seen  into  spoken  words  before 
they  are  understood.  In  both  instances  one  usually 
translates  into  ideas  at  once.  Other  objects  are  perceived 
in  the  same  way  and  by  the  same  laws.  Any  object  gives 
a  few  sensations  that  correspond  to  the  letters  or  form 
of  the  words,  while  the  object  that  is  seen  corresponds 
to  the  words  or  to  the  ideas  that  are  read.  The  distinc- 
tion between  the  mere  sensations  and  the  appreciated 
object  cannot  always  be  made  out  so  clearly,  but  the 
same  laws  hold  in  the  instances  so  far  analysed. 


196 


THE  ESSENTIALS  OF  PSYCHOLOGY 


FIG.  27.  —  (From 
Titchener, 
'  Experimental 
Psychology,' 
vol.  i,  pt.  i,  p. 
160.) 


Optical  Illusions.  —  One  of  the  clearest  demonstra- 

tions of  the  dependence  of  perception  upon  interpreta- 

tion in  the  light  of  earlier  experience  is  found  in  the  fact 
and  nature  of  illusions.  In  all  forms  of 
perception  what  is  seen  or  heard  frequently 
proves,  on  closer  examination,  not  to  have 
had  real  existence  in  the  outside  world,  or 
to  have  existed  in  some  other  form  than 
that  in  which  it  was  perceived.  The  illu- 
sion is  due  to  one  of  two  causes.  The 
sensations  suggest  the  wrong  memories  or 
ideas,  either  because  of  close  associations, 
or  because  the  wrong  context  or  setting  is 

dominant  at  the  moment.     The  influence  of  close  asso- 

ciation is  most  clearly  shown  in  optical  illusions  of  space. 

One  interpretation  of  a  number  of  illusions  is  that  they 

are  due  to  a  sug- 

gestion   of    per- 

spective where  it 

does  not  belong. 

One  of  the  most 

general    applica- 

tions of  this  law 

is   the    tendency 

to     overestimate 

small  angles  and 


\J 


FIG.  »8.  —  Poggendorff  illusion.     (From  Titchener; 
op.  cit.,  p.  165.) 


to  underestimate 

obtuse       angles. 

Square  surfaces  are  nearly  always  seen  in  perspective, 

which  makes  right  angles  appear   to  be  either  acute 

or  obtuse.     The  most  frequent  association  with  these 


OPTICAL  ILLUSIONS  1 97 

angles  is  a  right  angle,  —  an  overestimation  of  the 
small  and  an  underestimation  of  the  large  angle.  This 
association  which  has  become  fixed  through  the  great 
preponderance  of  rectangular  objects  leads  to  error 
in  many  different  cases.  A  circle  with  a  square  in- 
scribed seems  broken  at  the  corners  of  the  square, 
as  may  be  seen  in  Figure  27.  Where  an  oblique  line 
cuts  a  plane  figure  or  two  plane  figures,  the  sections 
of  the  line  seem  not  to  be  continuous.  (See  Fig.  28.) 
Both  illusions  can  be  referred  to  the  overestimation  of 


FIG.  2Q.  —  Hering  figure.     (From  Titchener,  op.  cit.,  p.  161.) 

small  angles.  A  more  complicated  figure,  that  may  be 
explained  as  due  to  the  overestimation  of  small  angles 
or  more  directly  as  a  misapplication  of  a  perspective 
interpretation,  is  the  Hering  figure  (Fig.  29).  In  this 
figure,  the  oblique  lines  are  taken  to  represent  parallel 
lines  converging  toward  a  vanishing  point;  and  as 
straight  lines  drawn  on  such  surfaces  would  represent 
curved  lines,  the  parallel  lines  are  assumed  to  diverge  in 
the  middle.  This,  too,  can  be  explained  as  a  result 
of  overestimation  of  small  angles.  In  all  of  these  cases, 
the  figure  has  been  closely  associated  with  the  wrong 


THE   ESSENTIALS   OF  PSYCHOLOGY 


interpretation,  and  the  interpretation  replaces  the  actual 
figure.  Other  illusions  are  apparently  due  to  a  com- 
parison of  parts  of  the  figure  that  are  not  directly  in- 
volved. The  best  known  of  these  is  the  so-called  arrow- 


FIG.  30.  —  Muller-Lyer  illusion.     (From  Titchener,  op.  tit.,  p.  159.) 

head  or  Muller-Lyer  figure  (Fig.  30).  The  distance 
bounded  by  turned-out  arrow-heads  seems  much  larger 
than  that  bounded  by  those  that  turn  in.  It  is  prob- 
able that  one  really  judges 
the  enclosed  area,  rather 
than  the  distance  from 
angle  to  angle.  The  per- 
spective explanation  has 
been  applied  to  this  figure 
also,  on  the  assumption 
that  one  figure  represents 
a  book  opened  away  from 
the  observer,  the  other  a 
book  opened  toward  the 
observer.  This  makes  one  line  seem  more  distant  and 
thus  larger  than  the  other.  Another  illusion  due  to 
the  surroundings  is  the  underestimation  of  the  upper 
of  the  two  identical  figures  (Fig.  31).  The  upper  one 
seems  smaller  because  one  expects  both  to  be  bounded 


FIG.  31.  —  (From  Titchener,  op.  cit.,  p. 
166,  after  Wundt.) 


OPTICAL  ILLUSIONS  1 99 

by  the  same  radii;  the  failure  to  extend  to  that  line 
makes  it  seem  shorter  than  the  lower.  A  very  large 
number  of  optical  illusions  are  due  to  the  effects  of 
associations  similarly  misapplied,  and  a  large  number 
may  be  brought  under  these  two  principles  of  misin- 
terpretation of  perspective,  and  of  arousal  of  associates 
by  the  surroundings. 

Illusions  illustrating  the  same  principle  of  the  arousal 
of  wrong  associates  may  be  found  in  any  field.  It  has 
been  said  that  one  frequently  ascribes  motion  to  the 
wrong  object.  When  standing  on  a  bridge  over  a 
rapidly  flowing  stream,  one  can  easily  believe  that  the 
bridge  is  moving  upstream  and  the  water  is  stationary. 
This  is  due  to  the  fact  that  the  smaller  object  is  ordinarily 
in  motion,  the  ground  or  the  whole  field  of  vision  very 
seldom.  The  interpretation  more  frequently  associated 
with  the  sensations  asserts  itself  against  the  less  fre- 
quent. The  overlooking  of  misprints  in  reading  has  the 
same  explanation,  as  has  the  shadow  lines  in  the  letters 
in  Figure  22,  page  171.  Many  misinterpretations  of 
common  objects  can  be  referred  to  the  same  law.  Illu- 
sions due  to  the  dominance  of  the  wrong  context  or  to 
the  wrong  attitude  are  also  numerous.  If  one  is  expect- 
ing any  object,  anything  at  all  like  it  may  be  mistaken 
for  it.  If  one  is  listening  for  the  footsteps  of  one  person, 
any  passer-by  may  be  mistaken  for  him.  When  hunting 
for  cows  in  the  dark,  any  bush  or  dark  spot  takes  on  the 
form  of  the  cow.  Any  preconception  or  situation  that 
favours  one  interpretation  is  likely  to  arouse  associates 
that  constitute  a  misinterpretation  or  illusion.  In 
general,  illusions  are  due  to  wrong  suggestions  by  sensa- 


200        THE  ESSENTIALS  OF  PSYCHOLOGY 

tions,  either  because  of  the  greater  strength  of  the  inap- 
propriate association,  or  because  the  wrong  mental 
attitude  is  dominant.  Illusions  follow  the  same  laws 
as  perceptions ;  the  only  difference  is  that  in  the  illusion 
the  interpretation  is  proved  false  by  later  observation 
under  more  satisfactory  conditions. 

Hallucination.  —  Hallucinations  are  closely  related  to 
illusions.  Hallucinations  have  a  slighter  basis  in  sen- 
sation than  illusion,  and  derive  more  from  association. 
An  illusion  is  always  a  misinterpretation  of  an  object, 
while  in  hallucination  there  is  no  apparent  basis  for  the 
perception  in  sensation.  It  is  probable  that  the  absence 
of  sensation  is  in  most  cases  only  apparent,  and  that  the 
sensational  basis  may  be  found  in  some  slight  stimula- 
tion, as  in  the  after-image  for  the  visual  hallucination, 
and  in  the  circulation  or  some  abnormal  condition  of 
the  middle  ear  for  auditory  hallucination.  Even  in  the 
insane,  who  are  most  subject  to  hallucination,  there  is 
considerable  evidence  that  the  presence  of  the  false  ex- 
perience is  determined  by  some  obscure  stimulation  of  a 
sense-organ  which  is  misinterpreted  and  referred  to  the 
outer  world.  Thus  a  patient  may  insist  that  he  is  con- 
stantly hearing  voices  when  no  one  else  hears  them,  and 
with  no  apparent  cause.  On  examination  it  is  found 
that  he  suffers  from  a  disease  of  the  ear  that  produces  a 
constant  ringing  in  the  ear,  and  this  has  been  misinter- 
preted to  give  rise  to  the  hallucination.  The  only  dif- 
ference between  this  and  an  illusion  is  that  the  illusion 
is  excited  by  some  slight  objective  sound  as  when  one 
mistakes  the  rustling  of  leaves  for  an  approaching  car. 

Summary.  —  Perception  in  all  of  its  phases,  then,  is 


PERCEPTION  201 

due  to  the  interpretation  of  present  sensations  by  or- 
ganised earlier  experiences.  The  character  of  the  per- 
ception depends  upon  the  sensory  stimulus, the  developed 
ideas  the  individual  has  at  his  command,  and  the  con- 
nection between  these  and  the  sensations.  In  all  cases 
of  perception,  the  result  is  accepted  as  a  thing  in  the 
outside  world,  and  this,  the  final  outcome  of  the  process, 
is  the  only  part  that  is  noticed ;  all  else  is  overlooked. 

QUESTIONS 

1.  How  is  a  percept  different  from  a  sensation? 

2.  What  do  associates  add  to  perception? 

3.  Why  do  you  see  the  same  thing  differently  at  different 
times?    Wrhat  changes? 

4.  In  what  ways  are  things  different  from  percepts?    from 
sensations? 

5.  Is  space  a  thing ?    If  not  how  are  the  two  related? 

6.  What  is  a 'local  sign'? 

7.  Describe  the  mechanism  by  which  the  lens  accommodates 
itself  to  different  distances. 

8.  Why  are  two  eyes  more  accurate  than  one  in  estimating 
distances? 

9.  Do  you  see  double  images  ordinarily?    If  not  what  influence 
have  they  in  distance  perception?    If  you  answer  'yes'  in  what 
sense  do  you  use  the  term  'see'? 

10.  How  does  the  estimation  of  the  direction  of  a  sound  differ 
in  the  two  different  planes :  the  vertical  between  the  ears  and  the 
vertical  through  the  ears? 

11.  Illustrate  from  reading  the  three  processes  of  perception. 

12.  In  what  two  ways  do  we  estimate  the  length  of  a  time 
interval  ? 

13.  What  are  the  possible  misplaced  associates  in  the  Miiller- 
Lyer  illusion  ? 

14.  Explain  the  illusion  in  Figure  31. 


202  THE   ESSENTIALS   OF   PSYCHOLOGY 

EXERCISES 

1.  Move  the  finger  in  a  circle  before  the  face  with  closed  eyes. 
Do  you  appreciate  the  motion  in  the  arm  or  do  you  see  it  with  the 
mind's  eye  ?    How  is  the  picture  suggested  ? 

2.  Have  some  one  touch  you  on  the  wrist  while  the  eyes  are 
closed.    Try  to  touch  the  point.    Measure  the  error  and  repeat 
twenty  times.    Average.    Is  the  first  touch  more  or  less  accurate 
than  the  point  finally  decided  upon?    How  do  you  know  what 
point  was  touched? 

3.  Compare  two  lines  20  and  21  mm.  in  length.     Can  you  tell 
which  is  the  longer?    Do  the  eyes  move  in  the  comparison?    Can 
you  compare  with  the  eyes  stationary? 

4.  Draw  a  horizontal  line  20  mm.  long.    Without  measuring  try 
to  place  a  point  20  mm.  above  one  end  of  the  line.     Measure  the 
distance.     Repeat  twenty  times.    Average.    Explain  result.    Re- 
peat, putting  the  point  above  the  centre  of  the  line.    How  do  the 
results  compare  ?    Explain  the  difference. 

5.  Wave  a  candle  or  incandescent  electric  lamp  about  to  one 
side  of  the  line  of  sight  in  an  otherwise  dark  room.    Note  the 
shadows  of  the  retinal  blood  vessels.    Why  are  they  seen  outside 
of  the  eye?     Can  you  change  their  apparent  position  by  looking 
at  different  distances?    Why? 

6.  Hold  a  bottle  with  a  label  on  it  about  30  cm.  before  the  nose. 
Close  first  one  eye,  then  the  other.    Note  the  difference  in  the 
images.     Place  the  bottle  six  metres  away.     Compare  the  images 
as  before.    Where  is  the  difference  between  the  images  greater? 
Can  you  see  the  difference  in  the  images  with  both  eyes  open? 
What  is  the  bearing  upon  the  perception  of  distance  ? 

7.  Hold  the  index  fingers  25  cm.  apart  before  the  eyes.    Look 
at  the  more  distant  finger  and  note  the  double  images  of  the  nearer. 
Close  one  eye.    Which  image  vanishes?    Look  at  the  nearer 
finger.    Which  image  of  the  more  remote  finger  vanishes  when  one 
eye  is  closed?    Look  at  a  point  6  m.  distant.     Can  you  notice  the 
douoie  images  ot  nearer  and  more  remote  objects?    How  do  the 
double  images  vary  in  distance  from  each  other  as  they  depart  from 
the  point  of  fixation  ? 


PERCEPTION  203 

8.  Have  some  one  tap  a  two-second  interval  and  attempt  to  re- 
produce the  interval.     How  accurate  are  you?     Can  you  notice 
strain  or  other  sensations  during  the  interval?    Do  they  seem  to 
affect  the  comparison? 

9.  Give  a  group  of  students  an  interval  of  about  two  minutes, 
first  when  doing  nothing,  and  then  while  adding.    Ask  them  which 
is  longer.     Explain. 

10.  Watch  the  eyes  of  some  one  when  reading  at  the  ordinary 
rate.    How  many  pauses  do  the  eyes  make  to  the  line  on  the 
average?     Compare  reading  a  newspaper  with  a  page  of  an  un- 
familiar chapter  of  this  text.    Try  when  reading  to  detect  mis- 
prints.   In  which  instance  are  the  words  relatively  prominent 
as  compared  with  ideas? 

1 1 .  Draw  a  vertical  line  with  an  oblique  line  across  it.     Can  you 
see  the  figure  as  a  cross  with  the  arm  perpendicular  to  the  upright, 
but  in  some  other  plane  than  the  plane  of  the  paper?    What  bear- 
ing has  this  upon  the  interpretation  of  the  illusion  of  overestimation 
of  small  angles? 

REFERENCES 

ANGELL  :  Psychology,  ch.  vi. 

TITCHENER  :  Text-book  of  Psychology,  pp.  303-374. 

JTIDD  :  Psychology,  ch.  vi. 

PILLSBURY  :  Attention,  ch.  viii. 

JASTROW  :  Fact  and  Fable  in  Psychology,  pp.  275-295. 

SEASHORE  :  Elementary  Experiments  in  Psychology,  ch.  iv-vi,  xiv. 


CHAPTER  VIII 
MEMORY  AND   IMAGINATION 

MEMORY,  imagination,  and  reasoning  are  related  to 
simple  imagery  very  much  as  perception  is  related  to 
sensation.  Each  may  be  analysed  into  simple  sensa- 
tional or  imaginal  qualities,  and  each  follows  the  laws  of 
association.  Each  deals  with  things,  is  concrete,  as 
opposed  to  sensations  and  images  which  are  pure  abstrac- 
tions. Each  is  an  attempt  to  understand  the  world  and 
prepares  for  action  in  the  world.  The  thought  processes 
differ  from  perception  in  the  time  and  place  to  which 
the  event  is  referred.  In  perception  it  is  actually  pre- 
sented to  the  senses  at  the  moment ;  in  the  three  pro- 
cesses under  discussion  it  is  regarded  as  past  or  future  or 
as  having  real  existence  in  some  distant  place.  The  only 
other  difference  is  that  perception  contains  some  sensa- 
tional elements,  while  the  others  are  altogether  of  central 
origin.  Memory,  imagination,  and  reasoning  differ  from 
each  other,  also,  in  the  temporal  reference  and  the  atti- 
tude that  is  taken  toward  the  object  or  event  which  they 
represent.  Memories  are  all  ascribed  to  the  past,  while 
reasoned  and  imagined  events  may  be  past,  present, 
or  future.  Memories  and  the  results  of  reasoning,  again, 
are  accepted  as  true,  imaginings  are  without  implication 
of  truth.  Otherwise  they  are  not  to  be  distinguished. 
Each  may  be  made  up  of  the  same  elements.  One  may 
204 


MEMORY  205 

imagine  an  event,  later  reason  that  it  is  sure  to  happen, 
have  this  conclusion  confirmed  by  the  outcome,  and  later 
remember  it,  —  all  in  the  same  imagery.  They  are  all 
three  suggested  and  determined  in  their  course  by  the 
laws  of  association.  Not  the  materials  or  the  origin 
distinguish  these  states  from  each  other,  but  the  attitude 
taken  toward  them  and  the  points  in  time  and  space  to 
which  they  are  referred. 

The  Phases  of  the  Memory  Process.  —  We  may  begin 
our  discussion  of  thought  processes  with  memory. 
Memory  is  a  reinstatement  of  an  old  experience,  or  a 
present  consciousness  of  an  old  experience,  with  the 
knowledge  that  it  is  old.  Four  fairly  distinct  processes 
are  involved  in  memory,  —  learning,  retention,  recall, 
and  recognition.  These  cannot  always  be  distinguished 
in  practice,  but  they  require  separate  treatment  if  mem- 
ory is  to  be  understood.  Any  one  of  them  would  be 
valueless  without  the  others.  Learning  without  reten- 
tion is  almost  a  contradiction  in  terms.  Retention 
without  recall  is  equally  futile.  Retention,  in  fact,  can 
be  demonstrated  only  through  recall.  The  knowledge 
stored  in  your  brain  at  this  moment  gives  no  sign  of  its 
presence.  You  can  be  aware  of  what  you  know  only 
by  recalling  it.  Finally,  if  events  when  recalled  were 
not  recognised,  recall  would  be  valueless.  If  when  an 
idea  came  to  mind  you  could  not  say  whether  it  was 
derived  from  a  dream  or  a  real  experience,  it  would 
be  merely  confusing.  Statements  that  you  remember 
you  have  read  but  cannot  refer  to  a  definite  book  or  time 
can  be  little  relied  upon.  Each  of  these  processes  must 
be  taken  up  in  order. 


206  THE  ESSENTIALS   OF  PSYCHOLOGY 

Observational  Memory.  —  It  is  convenient  to  dis- 
tinguish between  memory  derived  immediately  from 
perception  and  memory  for  the  words  into  which  a  per- 
ception has  been  translated.  The  former  is  called 
observational  memory.  One  constantly  has  occasion 
to  recall  and  report  upon  events  or  objects  seen  when  one 
had  no  intention  of  remembering  them.  All  practical 
occupations  involve  memory  of  this  type  and  success 
in  many  of  them  is  dependent  upon  its  accuracy. 
Numerous  experiments  have  been  made  upon  individ- 
uals of  different  age  and  intelligence  to  determine  the 
number  of  objects  that  may  be  recalled  and  the  per- 
centage of  mistakes  that  will  be  made  in  reporting. 
Aside  from  their  general  interest,  the  results  determine 
the  amount  of  credence  to  be  given  the  statements  of 
witnesses  in  the  courts.  In  the  experiments  a  group  of 
objects  or  a  picture  is  shown  for  forty  or  fifty  seconds 
and  after  different  intervals  the  observers  are  asked  to 
write  what  they  can  remember.  In  other  experiments 
which  more  nearly  approximate  court  practice,  a  scene 
is  carefully  acted  and  report  made  upon  that. 

The  Fidelity  of  Testimony.  —  Recall  in  observational 
memory  depends  upon  three  factors :  the  accuracy  of 
observation,  the  completeness  of  retention,  and  the 
adequacy  of  recall.  The  first  depends  upon  the  direction 
of  attention,  and  the  correctness  of  interpretation. 
Attention,  of  course,  depends  upon  the  earlier  training 
and  the  momentary  attitude.  The  observer  sees  what 
will  give  an  answer  to  his  specific  questions  or  what 
earlier  experience  has  shown  to  be  important.  The 
questions  that  are  uppermost  also  depend  upon  the 


OBSERVATIONAL  MEMORY  207 

training,  particular  or  general.  One  who  has  par- 
ticipated in  many  experiments  knows  what  is  likely 
to  be  overlooked  and  makes  special  effort  to  observe 
that.  It  is  also  an  advantage  to  put  the  observations 
into  words  when  they  are  made.  If,  for  example,  one 
count  at  the  time  of  exposure  the  objects  in  the  picture, 
the  number  will  be  correctly  reported,  while  if  one  at- 
tempts to  count  from  the  memory  image  at  the  time  of 
recall,  mistakes  are  practically  certain.  The  experiments 
show  that  all  are  more  impressed  by  persons  and  their 
acts,  by  objects  and  space  relations,  than  by  quantities 
and  colours.  From  eighty  to  ninety  per  cent  of  the  first 
class  are  correctly  reported  as  compared  with  forty  or 
fifty  per  cent  of  the  second.  Younger  children  notice 
objects  and  persons  and  as  they  grow  older  appreciate 
space  relations  and  quantities,  and  finally  colours.  Their 
reports  increase  in  accuracy  with  age.  Everyone,  a 
child  especially,  is  likely  to  make  mistakes  in  perception 
by  the  addition  through  association  of  objects  or  parts  of 
objects  not  really  present.  This  error  increases  when 
one  observes  rapid  actions  or  when  one  is  under  the 
influence  of  emotion. 

True  forgetting  is  relatively  slow  for  material  that 
has  been  put  into  words  after  observation.  Two  ex- 
periments show  an  increase  in  errors  of  one  third  of  one  per 
cent  a  day.  Much  more  important  are  the  influences 
that  affect  recall..  In  writing  the  report  there  is  always 
a  tendency  to  add  to  the  actual  observation  what 
is  only  inferred.  These  additions  are  supplied  by 
suggestion  and  are  mistaken  for  real  memories. 
Questions  greatly  increase  this  tendency  since  they 


208  THE   ESSENTIALS   OF   PSYCHOLOGY 

suggest  objects  which  are  either  not  observed  or  only 
vaguely  remembered.  When  left  free  to  describe  an 
experience  in  his  own  way,  the  individual  makes  from 
ten  to  twenty-five  per  cent  fewer  mistakes  than  when 
questioned,  even  when  the  questions  are  as  free  from 
suggestions  as  possible.  When  the  question  is  in  any 
degree  leading,  the  number  is  greatly  increased.  If 
one  ask  a  class  to  give  the  colour  of  an  object  that  is 
not  in  the  picture,  as  many  as  twenty  per  cent  may 
comply.  Children  are  much  more  influenced  by  sug- 
gestion than  adults  and  so  their  testimony  is  much  less 
to  be  relied  upon.  The  same  holds  of  a  witness  on  the 
stand.  Cross  questioning  always  decreases  the  accuracy, 
although  it  brings  out  points  that  would  not  be  thought 
of  unaided  and  so  is  necessary.  It  may  also  be  added 
that  subjective  assurance  is  not  a  satisfactory  warrant 
for  truth.  Statement  under  oath  is  only  a  little  more 
correct  than  ordinary  assertion. 

Rote  and  Logical  Memory.  —  In  everyday  life  we  put 
most  emphasis  upon  the  retention  and  recall  of  events 
as  described  in  words.  Written  and  spoken  words 
have  so  large  a  place  in  school  and  in  social  life  in  general 
that  verbal  memory  is  assumed  to  include  all  memory. 
In  dealing  with  it  we  may  disregard  the  errors  of  obser- 
vation and  emphasise  the  real  memory  processes.  In 
all  discussions,  it  is  essential  to  recognise  two  distinct 
forms,  rote  memory  and  logical  memory.  In  rote  learn- 
ing connections  are  formed  between  the  successive  ideas 
or  elements  to  be  learned,  and  recall  is  always  from 
one  to  another  of  these  elements.  In  logical  learning, 
on  the  contrary,  the  material  to  be  learned  is  connected 


MEMORY  209 

with  the  organised  knowledge  of  the  individual ;  it  is 
understood,  and  learned  because  it  is  understood. 
Most  learning  in  everyday  life  is  of  the  logical  sort. 
We  acquire  ideas,  not  mere  words,  and  the  ideas  are 
assimilated  at  once  with  the  ordered  experiences.  This 
is  much  quicker  and  more  effective  than  rote  learning. 
We  must  consider  both  forms  in  each  stage  of  the 
memory  process. 

Experimental  Methods.  —  Practically  all  of  the  ex- 
perimental work  in  memory,  of  which  there  has  been 
a  great  volume  in  recent  years,  has  dealt  with  rote 
learning.  Nonsense  syllables  were  chosen  as  the  ma- 
terial to  be  learned  in  these  experiments,  since  these 
were  entirely  new  to  all  of  the  learners  and  hence  should 
be  equally  easy.  Nonsense  syllables  were  made  by  plac- 
ing a  vowel  between  pairs  of  consonants  and  eliminat- 
ing all  of  the  combinations  that  made  words.  From  these 
syllables  series  of  from  eight  to  sixteen  were  chosen  and 
shown  to  the  learner  at  regular  intervals.  The  number 
of  times  the  series  were  shown  was  recorded.  Tests 
as  to  the  amount  retained  were  made  after  different 
intervals  to  measure  the  amount  of  retention,  and  thus 
to  determine  the  relative  value  of  the  methods  of  learn- 
ing. A  large  number  of  results  have  been  obtained  from 
these  experiments,  and  we  can  profitably  begin  our  dis- 
cussion of  the  memory  process  by  a  summary  of  certain 
of  the  more  important  laws  thus  established. 

The  Laws  of  Learning.  —  Learning,  the  first  step  in 
memory,  is  only  a  process  of  forming  associations.  Rote 
learning  is  primarily  a  process  of  forming  associations 
between  series  of  words  or  events,  —  in  the  experiments 


210  THE   ESSENTIALS    OF   PSYCHOLOGY 

we  are  considering,  connections  were  formed  between 
nonsense  syllables.  The  experiments  were  devised  to 
determine  the  best  methods  of  establishing  these  con- 
nections. The  results  may  be  stated  in  a  series  of  brief 
laws. 

1.  Learning  is  closely  dependent  upon  the  number 
of  repetitions.     If  four  repetitions  induce  a  given  liability 
to  recall,  eight  will  give  approximately  double  the  lia- 
bility,  and   others   in  proportion.     Probably   the  first 
repetitions  are  relatively  more  effective  and  after  a  large 
number  the  effect  of  each  is  relatively  less,  but  between 
eight  and  sixty-four  repetitions  each  has  approximately 
the  same  value.     It  is  important  to  note  in  this  experi- 
ment that  the  series  could  be  repeated  without  mis- 
take after  thirty-one  repetitions.     This  means  that  after 
the  learning  is  apparently   complete,    the  added  repe- 
titions increase  retention  although  at  the  moment  no 
effect  is  apparent. 

2.  Capacity  for  learning  increases  with  age  up  to  the 
period  of  maturity,  and  then  remains  constant  until  the 
beginning  of  old  age.     The  popular  belief  that  children 
learn  better  than  adults  has  no  basis  in  fact.     It  is 
due   apparently   to   the   child's   closer   observation   of 
routine  events,  and  to  the  frequency  with  which  events 
of  childhood  are  recalled  on  account  of  their  original 
interest.     When  tested  in  any  accurate  way,  the  child 
is  found  to  learn  less  easily  and  to  retain  less  well  than 
the  adult. 

3.  Distributed   Repetitions  more  Effective  than  Ac- 
cumulated. —  Learning  is  easier  if  the  repetitions  be 
distributed  over  several  days,  rather  than  accumulated 


LAWS   OF   LEARNING  211 

on  a  single  day.  With  twenty-four  repetitions,  two 
repetitions  on  each  of  twelve  days  are  more  effective 
than  four  repetitions  on  six  days,  or  six  on  four  days. 
Any  distribution  will  be  better  than  to  have  twenty-four 
on  one  day.  In  general  the  most  effective  distribution 
is  one  repetition  every  other  day.  This  is  due  largely 
to  the  fact  that  the  change  induced  in  the  nerve-cells 
by  learning  increases  during  the  period  between  repe- 
titions. The  new  repetitions  add  more  to  the  old  when 
its  effects  have  had  time  to  'set/  —  to  become  more 
completely  incorporated  in  the  nervous  tissue.  It  is 
a  common  observation  that  a  lesson  is  better  learned 
if  one  will  prepare  it  on  one  day  and  review  it  the  next 
morning,  than  if  one  prepares  it  more  thoroughly  at  the 
first  sitting,  —  an  instance  of  distributed  repetitions. 

4.  Learning  as  a  Whole  vs.  Learning  by  Parts.  —  In 
learning  a  selection,  it  is  advisable  to  read  through  the 
whole  from  beginning  to  end,  and  to  repeat  the  reading 
until  all  is  learned,  rather  than  to  learn  bit  by  bit.  If 
one  attempts  to  learn  a  poem  line  by  line  or  stanza  by 
stanza,  one  makes  a  number  of  unnecessary  and  mis- 
leading associations  between  the  ends  and  the  begin- 
nings of  lines  that  both  waste  time  and  interfere  with 
the  correct  associations.  Then,  too,  learning  by  parts 
leads  to  the  repetition  of  the  first  portions  more  fre- 
quently than  is  necessary,  since  they  are  repeated  with 
each  of  the  later  parts.  The  only  objection  to  learning 
by  wholes  is  that  one  is  likely  to  lose  interest  in  the 
work  when  no  progress  can  be  noticed,  and  to  read 
more  slowly  than  usual.  This  may  be  obviated  by 
making  pauses  at  the  natural  points  of  division  without 


212        THE  ESSENTIALS  OF  PSYCHOLOGY 

going  back  to  the  beginning.  It  is  also  advisable,  after 
the  selection  is  partly  learned,  to  repeat  the  harder 
parts  more  frequently  than  the  easier.  These  methods 
combine  the  marked  advantage  of  learning  as  a  whole 
with  the  greater  interest  that  comes  from  observing 
progress  in  the  task.  When  this  rule  was  observed, 
some  investigators  demonstrated  a  saving  of  from 
twenty  to  fifty  per  cent  in  the  repetitions  required  for 
learning. 

5.  Dependence  upon  Rate  of  Repetition.  — Learning 
is  quickest  if  the  rate  of  repetition  is  as  fast  as  is  con- 
venient for  the  man  who  is  learning.     Slower  repetitions 
waste  time  and  permit  distraction ;    faster  distract  at- 
tention from  the  learning  to  the  articulation.     As  many 
as  two  hundred  syllables  a  minute  have  been  found 
most    advantageous    for    some    individuals.     When    a 
student  has  been  compelled  to  postpone  preparation 
of  a  lesson  to  a  short  period  before  the  recitation,  unex- 
pected results  are  shown  for  the  time  spent.     Rapid 
reading  is  of  less  value  for  material  that  requires  thought 
than  for  rote  learning.     Slower  reading  permits  the  for- 
mation of  more  associates ;    rapid  reading  gives  strong 
associates  with  the  preceding  and  succeeding  elements, 
but  gives  no  time  for  others  that  might  be  important. 
Slow  reading  is  better  at  first ;  more  rapid  later,  when 
the  material  has  been  partly  learned. 

6.  Rhythm  Aids  Learning.  —  Rhythm  is  a  great  aid 
to  learning.     It  is  difficult  to  avoid  rhythm,  and  best 
results  may  be  obtained  from  a  rhythm  adapted  to  the 
material  and  to  the  individual  peculiarities  of  the  learner. 
The  strongest  connections  are  made  between  the  elements 


LAWS    OF    LEARNING  213 

of  the  rhythmic  unit.  When  the  rhythm  is  changed  or 
elements  are  given  a  place  in  a  new  unit,  relearning  or 
retention  is  much  interfered  with.  The  importance  of 
rhythm  is  shown  by  the  ease  with  which  blank  verse 
may  be  learned. 

7.  Learning  is  much  quicker  if  the  material  is  re- 
peated with  the  intention  of  recall.     Sanford  found  that 
he  could  remember  very  little  of  the  Morning  Prayer 
which  he  had  read  more  than  five  thousand  times.     With 
the   intention  of   recalling,  twenty  repetitions   should, 
at  a  conservative  estimate,  give  complete  learning. 

8.  Active  repetitions  are  of  more  value  than  passive. 
If  one  tries  to  repeat  from  memory  as  soon  as  possible, 
fewer  repetitions  are  required   than  if  one   continues 
passive    readings.     Witasek   found    that    learning   was 
quickest  with  six  readings  and  fifteen  attempted  repe- 
titions. 

9.  Associative  Inhibition.  —  Ideas  learned  in  one  con- 
nection seem  to  be  more  difficult  to  learn  in  another 
connection.     If  idea  '  A  '  has  been  learned  in  connection 
with  an  idea  '  £,'  it  will  be  more  difficult  to  learn  it  in 
connection  with  another  idea  '  C/  than  if  the  other 
association  had  not  been  formed.     Learning  anything 
incorrectly  makes  correct  learning  more  difficult.     The 
wrong  associations  check  the  formation  of  the  correct 
associations.     Associative    inhibition    is    present    only 
when  the  first  set  of  associates  has  not  been  completely 
formed.     After  complete  learning,  the  one  set  of  asso- 
ciations may  make  easier  the  formation  of  others  of  the 
same  kind.     If,  for  example,  one  has  partly  learned  one 
style  of  typewriter  key-board,  it  is  much  more  difficult 


214  THE   ESSENTIALS   OF   PSYCHOLOGY 

to  learn  another;  but  if  the  first  has  been  thoroughly 
learned  before  one  begins  the  second,  the  second  will  be 
learned  more  quickly  than  the  first.  The  same  holds  in 
some  degree  of  learning  languages. 

All  learning,  then,  is  a  process  of  forming  associations ; 
and  all  rote  learning,  with  much  of  other  learning,  de- 
pends for  its  adequacy  upon  the  use  of  suitable  methods 
of  repetition.  To  translate  into  nervous  terms,  learning 
is  a  process  of  producing  changes  in  the  synapses.  This 
change  depends  directly  upon  the  number  of  repetitions, 
upon  the  age  of  the  individual,  upon  the  time  that 
elapses  before  one  repetition  is  succeeded  by  another, 
and  by  the  rhythm  and  rate  of  repetitions.  Proper 
control  of  these  factors  and  of  attention  gives  the  means 
of  easiest  and  most  complete  learning. 

RETENTION  AND   FORGETTING 

If  learning  is  the  result  of  producing  changes  in  the 
synapses,  retention  depends  upon  the  persistence  of  the 
impression,  forgetting,  upon  its  disappearance.  That 
the  impressions  fade  and  gradually  disappear  with  the 
passage  of  time  is  obvious,  but  the  rate  of  disappear- 
ance and  the  conditions  that  favour  or  retard  the  dis- 
appearance can  be  determined  only  by  experiments. 
The  same  procedure  that  gave  us  the  laws  of  learning 
has  also  developed  a  series  of  laws  of  forgetting.  We 
may  summarise  these  as  before. 

i.  Rate  of  Forgetting.  —  Forgetting  goes  on  very 
rapidly  at  first,  then  more  slowly,  until  finally  there  is 
no  appreciable  change  even  over  long  periods  of  time. 
Ebbinghaus  found  that  with  series  of  nonsense  syllables, 


RETENTION  215 

half  of  the  learning  was  lost  in  the  first  hour ;  two-thirds 
the  first  day ;  while  at  the  end  of  the  month,  less  than 
four-fifths  was  forgotten.  Radossawljewitsch  obtained 
the  same  general  law,  but  with  a  slower  rate  of  forgetting 
for  the  shorter  periods.  In  ordinary  learning,  details 
disappear  very  quickly,  while  the  more  general  principles 
are  remembered  for  a  long  time.  Both  in  sense  and 
nonsense  material,  traces  of  learning  persist  long  after 
all  possibility  of  recall  in  the  ordinary  way.  In  the 
experiments,  the  amount  of  forgetting  is  measured  by 
comparing  the  number  of  repetitions  needed  for  relearn- 
ing  after  the  lapse  of  some  definite  time  with  the  number 
of  repetitions  used  in  the  original  learning.  Thus,  if 
sixteen  repetitions  are  required  for  learning  a  series  of 
twelve  syllables,  eight  repetitions  may  be  necessary  to 
relearn  at  the  end  of  the  hour.  After  three  days,  no 
single  one  of  the  syllables  can  be  recalled  off-hand,  but 
all  can  be  relearned  in  ten  repetitions.  In  much  practical 
learning,  the  same  rule  holds.  One  may  have  forgotten 
all  about  a  principle  in  arithmetic,  but  will  find  that  it 
can  be  relearned  in  a  fraction  of  the  time  originally  given 
it.  Not  a  little  of  the  benefit  of  learning  lies  in  this 
increased  ease  of  relearning,  even  where  nothing  can  be 
recalled  spontaneously.  Forgetting  is  much  slower 
for  sense  material  than  for  nonsense.  Ebbinghaus 
found  that  half  was  retained  at  the  end  of  twenty-four 
hours,  as  compared  with  one-third  for  nonsense  syllables. 
He  was  able  to  demonstrate  a  saving  of  seven  per  cent  in 
relearning  poetry  after  the  lapse  of  twenty-one  years. 

2.   Retroactive  Inhibition.  —  After  learning,  the  degree 
of  retention  is  affected  by  mental  activity  of  any  sort. 


2l6        THE  ESSENTIALS  OF  PSYCHOLOGY 

If,  after  learning  a  series  of  nonsense  syllables,  one  turns 
at  once  to  learning  something  else  or  to  any  other  form 
of  mental  work,  retention  is  sometimes  less  complete  than 
if  one  rests  a  few  minutes.  The  new  work  seems  to 
interfere  with  some  continuing  activity  of  the  nervous 
system  that  is  essential  to  the  best  retention.  This 
*  setting  '  of  the  associations  after  learning  is  probably 
what  makes  distributed  repetitions  more  effective  than 
accumulated  ones.  It  is  also  connected  with  the  memory 
after-image,  that  has  been  mentioned  in  previous  chap- 
ters (vide,  p.  145).  The  nerve-cells  continue  to  act  for 
some  little  time  after  the  conscious  processes  have  ceased 
and  the  associations  increase  in  strength  during  this 
period.  New  work  interferes  with  this  activity,  and 
prevents  the  associations  from  reaching  their  full 
strength.  This  so-called  retroactive  inhibition  is  anal- 
ogous to  the  retrograde  amnesia  of  the  psychiatrist. 
This  technical  term  means  that  a  mental  or  physical 
shock  will  destroy  memories  of  immediately  preceding 
events  which  may  be  assumed  to  be  represented  by 
associations  that  have  not  completely  '  set.'  A  blow 
upon  the  head  often  obliterates  the  memories  of  events 
that  have  occurred  for  a  half  hour  or  more  before.  An 
emotional  shock  may  have  the  same  effect.  In  our 
present  connection,  hard  mental  work  exerts  the  same 
influence  in  smaller  degree.  A  lesson  will  be  better 
remembered,  if  one  will  wait  three  to  six  minutes  after 
finishing  it  before  turning  to  another  task. 

3.  Individuals  who  learn  easily  seem  to  forget  slowly 
while  those  who  learn  slowly  forget  rapidly.  This  law 
holds  if  one  considers  pure  rote  learning.  When  learning 


RETENTION  2 17 

sense  material  by  logical  connections,  the  man  who 
learns  slowly  may  have  an  advantage  if  he  gives  the 
added  time  to  understanding  the  matter.  In  this  case 
the  evidence  shows  that  slow  learning  is  compensated  for 
by  retentive  memory.  The  conditions  and  results  are 
somewhat  in  dispute. 

All  learning  and  retention,  then,  are  dependent  upon 
the  formation  and  persistence  of  associations.  Learn- 
ing and  retention  are  never  of  ideas  or  things  in  isola- 
tion, but  always  of  things  in  connection.  The  only 
laws  that  affect  learning  are  the  laws  for  the  easy  and 
quick  formation  of  associations,  and  for  preventing  inter- 
ference with  them  when  they  are  formed.  No  new  prin- 
ciples need  be  added  to  the  discussion  of  association  to 
understand  rote  learning  and  retention. 

The  Advantages  of  Forgetting.  —  One  is  inclined  to 
think  of  forgetting  as  altogether  a  disadvantage.  A 
little  consideration  shows  that  on  the  contrary,  if  every- 
thing were  remembered,  it  would  probably  be  a  great 
misfortune.  Many  of  the  trivial  events  of  everyday 
life  are  very  much  better  forgotten.  Forgetting  is  an 
expression  of  the  selective  activities  of  consciousness, 
and  is  almost  if  not  quite  as  important  as  attention  in 
protecting  the  individual  against  the  unessential  events. 
Attention  very  largely  determines  what  shall  be  selected, 
both  for  observation  and  retention,  although  it  may 
work  different  results  for  each,  since  many  things  im- 
portant at  the  moment  are  not  worth  recalling.  Forget- 
ting plays  its  part  in  permitting  these  to  lapse  into  un- 
consciousness. A  good  memory  involves  a  certain 
amount  of  forgetting,  provided  only  the  right  things  are 


2l8  THE   ESSENTIALS   OF   PSYCHOLOGY 

forgotten.  Not  only  is  it  an  advantage  to  forget  the 
trivial  events  but  also  to  forget  things  that  were  learned 
wrongly.  If  one  remembered  everything,  the  bad  would 
survive  with  the  good.  As  it  is,  when  a  mistake  has 
been  made  and  corrected,  the  correction  may  be  re- 
membered, the  mistake  forgotten.  On  the  whole,  then, 
the  fact  that  the  memory  trace  in  the  nervous  system 
tends  to  disappear  is  an  advantage  rather  than  a  dis- 
advantage. In  some  cases  where  no  distinction  is  made 
between  the  important  and  the  unimportant,  the  in- 
dividual is  rendered  ineffective.  Slavery  to  detail  often 
leads  to  waste  of  time  and  effort  that  a  bad  memory 
might  prevent.  In  the  adequate  use  of  past  experiences 
forgetting  is  almost  as  important  as  remembering. 

RECALL 

The  laws  of  recall,  too,  are  primarily  the  laws  of 
association.  Just  as  everything  that  is  learned  must 
be  learned  in  connection  with  something  else,  so  any- 
thing that  is  recalled  must  be  recalled  because  of  the 
rearousal  of  an  associate.  This  can  be  brought  about 
only  through  the  presence  of  some  cue,  some  idea  as- 
sociated with  the  fact  essential  at  the  moment.  One 
cannot  recall  an  idea  without  the  associated  idea  or 
sensation.  It  is  impossible  to  get  back  the  fact  in  any 
other  way  than  through  the  appropriate  suggestion. 
This  suggestion  may  be  furnished  by  the  preceding  idea 
or  it  may  come  through  sensation.  Fortunately  nearly 
every  fact  has  been  associated  with  the  occasions  that 
make  its  return  desirable,  and  in  consequence  one  never 
suffers  from  or  even  notices  the  lack  of  more  direct  means 


RECALL  219 

of  recall.  The  desire  for  recall  brings  its  satisfaction, 
and  that  is  all  that  can  be  asked.  The  laws  of  recall 
come  into  prominence  only  when  they  fail  to  be  effective . 
Occasionally  one  is  certain  that  one  has  a  bit  of  knowl- 
edge that  would  be  desirable  at  the  moment,  but  which 
cannot  be  recalled.  Under  such  circumstances,  one  of 
two  factors  is  at  fault.  Either  no  association  has  been 
formed  between  the  idea  in  mind  and  the  idea  desired, 
or  the  mental  attitude  is  wrong  for  developing  that 
association.  These  are  the  conditions  for  the  return  of 
associations  discussed  in  Chapter  V.  The  one  can  be 
obviated  only  at  the  time  the  associations  are  formed, 
is  due  to  the  nature  of  the  learning ;  the  other  depends 
upon  the  condition  of  the  thinker  at  the  moment  of 
recall. 

Certain  and  accurate  recall  depends  primarily  upon 
the  methods  of  learning;  it  is  only  in  part  subject  to 
control  at  the  moment  of  recall.  The  only  rule  that  can 
be  given  for  the  improvement  of  recall  is  to  learn  a  new 
fact  in  connection  with  all  of  the  possible  situations 
that  may  require  its  application.  Most  learning  is 
in  one  connection  only  or  in  a  few  at  most.  The  value 
of  a  fact  increases  with  the  number  of  connections  that 
it  makes,  for  each  new  connection  makes  it  available  in 
a  new  place  and  at  a  new  time.  These  valuable  con- 
nections can  be  supplied  by  taking  time  to  think  of  the 
various  uses  that  a  new  fact  may  have,  or,  more  effec- 
tively, by  actually  applying  it.  A  formula  in  trigonom- 
etry will  be  impressed  much  more  surely  and  will  be 
recalled  in  many  more  appropriate  situations  if  a  num- 
ber of  problems  are  solved  by  it.  Each  of  these  ap- 


220  THE  ESSENTIALS   OF   PSYCHOLOGY 

plications,  when  they  appear  in  practice,  will  suggest 
the  principle;  while  without  them,  only  the  preceding 
statements  in  the  text  will  recall  it,  and  these  are  seldom 
present  when  the  principle  is  needed.  In  general,  learn- 
ing any  new  fact  in  all  its  useful  connections  will  insure 
perfect  recall  so  far  at  least  as  it  may  be  insured  at  the 
moment  of  learning. 

Attitude  Influences  Recall.  —  The  other  element  in 
recall  depends  upon  having  the  correct  attitude  toward 
the  situation  when  it  presents  itself.  If  one  does  not 
properly  appreciate  the  situation,  the  associates  that 
might  be  used  at  the  time  will  fail  to  be  recalled.  When 
one  is  looking  at  the  problem  from  the  wrong  standpoint 
a  number  of  solutions  that  harmonise  with  that  attitude 
will  present  themselves,  but  they  will  not  be  solutions 
of  this  problem.  Both  sorts  of  failure  to  recall  may  be 
observed  in  any  class  recitation.  When  a  question  is 
asked,  it  should  serve  as  a  cue  for  the  answer.  In 
many  if  not  most  cases,  the  failure  to  answer  does  not 
depend  upon  lack  of  knowledge,  as  is  proved  by  the  fact 
that  the  answer  will  be  recognised  when  it  is  given. 
What  is  wrong  is  the  failure  to  connect  the  answer  with 
the  question  at  the  time  it  was  learned.  It  was  learned 
in  some  other  connection,  and  is  useless  as  an  answer  to 
this  question.  In  the  second  place,  the  question  may  be 
understood  in  the  wrong  way.  The  question  may  have 
been  connected  with  the  answer  when  understood  in 
one  way,  but,  at  the  moment,  the  student  is  thinking 
of  the  question  in  one  way,  the  instructor  in  another. 
The  result  is  that  the  answer  suggested  does  not  meet 
the  problem  that  the  instructor  has  put.  Adequate 


RECALL  221 

recall  depends,  first,  upon  having  the  material;  then 
upon  having  the  knowledge  associated  with  an  idea  or  ob- 
ject present  when  that  bit  of  knowledge  is  needed  ;  and 
finally,  upon  being  in  a  suitable  attitude  toward  the 
situation.  The  first  two,  learning  and  learning  in  the 
right  connections,  can  of  course  be  insured  only  before 
the  time  at  which  the  knowledge  is  to  be  used.  The  at- 
titude is  the  only  factor  determined  at  the  time  of  recall, 
and  that  is  not  easily  controlled.  It  depends  upon  the 
agility  of  wit  of  the  thinker,  and  upon  the  things  he  has 
been  seeing  or  thinking  just  before.  The  most  that  can 
be  done  in  the  control  of  the  attitude  is  to  teach  the 
individual  to  look  at  a  situation  in  many  ways,  and  to 
trust  his  memory.  Taking  the  right  attitude  is  in  large 
part  due  to  native  endowment,  but  training  or  practice 
has  some  effect. 

Reproductive  Inhibition.  —  One  factor  similar  to 
associative  inhibition,  that  was  considered  in  discussing 
learning,  may  affect  recall.  This  is  reproductive  in- 
hibition. Associates  with  the  same  idea,  not  only  inter- 
fere with  each  other  in  the  formation,  but  also  prevent 
the  recall  of  the  ideas.  If  one  has  learned  '  A  '  with 
1  B,'  '  C,'  and  '  D,'  and  'A'  is  in  consciousness,  the 
recall  of  any  one  of  the  associates  may  be  prevented, 
or  at  least  delayed.  All  associates  tend  to  return,  and 
each  helps  to  prevent  the  return  of  the  others.  This 
mutual  interference  of  associates  is  probably  the  ex- 
planation of  many  cases  of  mental  blocking.  Often 
when  one  is  trying  to  recall  a  perfectly  familiar  fact, 
it  refuses  to  return.  It  seems  to  be  on  the  tip  of  the 
tongue,  but  cannot  be  expressed.  Later,  when  the 


222        THE  ESSENTIALS  OF  PSYCHOLOGY 

occasion  for  its  recall  has  passed,  it  will  return  with 
perfect  ease.  It  is  probable  that  the  cue  was  associated 
with  several  ideas,  and  that  they  mutually  prevented 
the  return  of  any  one.  When  recall  occurs,  probably  all 
but  one  of  the  associates  have  ceased  to  be  active. 
Ordinarily  some  one  associate  will  be  much  stronger 
than  the  others,  or  will  be  favoured  by  the  context  or 
'  mental  set,'  and  the  opposition  of  the  others  is  ineffec- 
tive. 

Logical  as  Opposed  to  Rote  Learning.  —  So  far,  we 
have  been  discussing  memory  as  if  all  associations  were 
farmed  at  once,  and  as  if  all  learning  dealt  with  entirely 
new  knowledge.  As  a  matter  of  fact,  however,  most 
learning  consists  in  bringing  the  new  material  into  con- 
nection with  old  knowledge,  or  in  seeing  old  knowledge 
in  new  lights.  When  one  is  reading  even  in  a  new  sub- 
ject, one  is  constantly  referring  what  is  read  to  earlier 
knowledge,  rather  than  taking  the  new  as  new.  We  can 
bring  ourselves  to  read  very  little  of  what  we  do  not 
understand,  yet  to  understand  means  nothing  more  than 
to  refer  the  new  to  old  knowledge  or  old  principles. 
What  is  understood  is  learned  very  quickly,  —  even  by 
a  single  repetition.  A  large  part  of  the  work  necessary 
for  learning  was  done  when  the  principles  themselves 
were  learned  and  does  not  need  to  be  done  again.  All 
that  is  necessary  is  to  connect  the  new  with  the  old,  and 
the  new  then  takes  on  the  permanence  of  the  old. 

The  advantages  of  logical  learning  are  twofold.  In 
the  first  place,  as  was  indicated  above,  when  one  under- 
stands, the  material  is  partly  known  already,  and  so 
needs  fewer  repetitions  to  be  remembered.  In  the 


LOGICAL  MEMORY  223 

second  place,  there  are  many  more  facts  than  principles, 
and  the  principles  are  used  so  frequently  in  different 
connections  that  they  become  part  of  the  permanent 
endowment.  Specific  instances  may  appear  and  be 
forgotten,  but  the  general  principles  illustrated  are  used 
over  and  over  and  thus  are  given  no  chance  to  be  for- 
gotten. When  the  new  fact  or  experience  is  understood 
by  being  referred  to  this  system  of  principles,  it,  too, 
comes  to  partake  somewhat  of  their  permanent  character. 
One  may  notice  in  the  simplest  affairs  the  difference 
between  the  bare  unaided  memory  and  this  memory  of 
general  principles.  In  playing  golf,  for  example,  one 
may  either  remember  in  a  vague  general  way  where  the 
ball  has  been  driven,  or  may  fix  the  place  by  specific 
reference  to  a  prominent  object.  If  one  merely  notices, 
one  may  at  once  walk  to  the  ball  with  no  other  thought 
than  that  one  is  going  in  the  right  direction.  Under 
ordinary  circumstances  this  suffices,  but  if  one  is  turned 
aside  to  hunt  the  ball  of  the  opponent,  or  the  stroke  is 
bad  and  arouses  an  emotion,  the  pure,  unmediated 
memory  is  destroyed ;  one  retains  but  the  vaguest  idea 
of  the  direction  of  the  ball.  If,  however,  one  refers  the 
position  to  some  fixed  point,  refers  it  to  a  system,  the 
position  will  be  remembered  in  spite  of  distraction,  and 
for  a  considerably  longer  time. 

Logical  Learning  more  Rapid  and  more  Permanent. 
—  Nearly  all  of  the  experiments  whose  results  have  been 
formulated  in  the  earlier  sections,  have  been  made  with 
nonsense  syllables.  Similar  experiments  with  sense 
material  learned  as  one  ordinarily  does  for  ideas  rather 
than  for  words  show  that  the  laws  stated  above  are  true 


224        THE  ESSENTIALS  OF  PSYCHOLOGY 

for  logical  as  well  as  for  rote  memory.  The  most  striking 
difference  between  the  two  forms  is  the  greater  ease  and 
permanence  of  logical  learning.  Ebbinghaus  found 
that  learning  poetry  verbatim  takes  less  than  half  the 
time  required  for  nonsense  syllables,  but  memory  for 
the  sense  of  ordinary  reading  matter  has  a  much  greater 
advantage.  Long  passages  that  would  require  days  for 
their  verbatim,  learning  can  be  appreciated  and  the  ideas 
retained  with  one  reading.  The  rate  of  forgetting  is  also 
much  slower.  A  fact  thoroughly  understood  may  be 
remembered  for  most  of  a  lifetime.  Accurate  experi- 
ments on  the  course  of  recognition  indicate  that  objects, 
that  may  be  referred  to  standards  or  general  principles, 
are  recognised  practically  as  well  after  a  longer  as  after  a 
shorter  time,  while  sensations,  to  which  no  names  can  be 
given  or  which  can  be  referred  to  no  general  principle, 
lose  their  value  for  recognition  at  about  the  same  rate 
as  that  at  which  nonsense  syllables  are  forgotten.  What 
experimental  evidence  there  is,  together  with  the  results 
of  observation,  indicates  that  logical  learning  is  very 
much  quicker  than  learning  of  nonsense  syllables,  and 
that  the  material  is  much  more  slowly  forgotten.  Most 
learning  is  of  ideas,  and  ideas  follow  logical  laws,  —  are 
learned  in  connection  with  principles  already  known 
rather  than  by  the  bare  laws  of  association.  In  con- 
sequence, the  usual  learning  is  much  quicker  and  for- 
getting much  slower  than  the  results  obtained  from 
experiments  on  nonsense  syllables  indicate.  The  one 
important  difference  is  that  what  is  essential  in  logical 
learning  is  the  formation  of  associations  between  the 
new  and  the  general  principles  that  explain  them,  rather 


LOGICAL  MEMORY  225 

than  the  formation  of  associations  between  successive 
elements. 

Cramming.  —  Recent  investigations  throw  consider- 
able light  upon  the  old  problem  of  cramming.     Cram- 
ming is  essentially  a  process  of  learning  by  accumulated 
repetitions.     In  recent  experiments  upon  material  learned 
for  its  ideas  rather  than  for  the  words,  accumulated 
repetitions  gave  as  good  results  as  distributed  when  tested 
twenty-four  hours  later,  while  the  divided  repetitions 
were  much  more  effective  after  two  weeks  or  a  month. 
This   harmonises   with   the   common   experience    that 
material  studied  intensively  just  before  one  needs  to 
use  it  can  be  recalled  fairly  accurately,  but  leaves  no 
permanent   impression;     while    the    work    learned    by 
various  repetitions  during  the  term,  even  if  it  be  no 
better  recalled  at  the  time  of  examination,  will  be  re- 
membered for  a  long  time.     Frequent  reviews  are  very 
valuable  for  the  permanent  retention.     Edwards  found 
that  four  minutes'  study  of  a  short  selection  with  two 
and  a  half  minutes'  review  a  few  days  later  gave  thirty 
per  cent  more  correct  responses  than  six  and  a  half 
minutes'  study  at  the  first  sitting.     In  addition  to  the 
probably    physiological    effect    of    divided    repetitions, 
frequent  return  to  a  topic  makes  it  possible  to  relate 
it  to  many  different  facts  and  thus  increase  the  number 
of  events  that  will  arouse  it.    Then,  too,  the  definite 
intention  to  learn   anything   for  a  particular   occasion 
seems  to  give  a  tendency  for  it  to  be  forgotten  when  that 
occasion  is  past.     Cramming  for  these  reasons  gives  only 
temporary  retention.     Lasting  knowledge  demands  faith- 
ful work  day  by  day  and  frequent  reviews. 

Q 


226  THE   ESSENTIALS   OF   PSYCHOLOGY 

General  Principles  Retained  Longer  than  Particular 
Facts.  —  Evidence  for  the  advantages  of  logical  learning 
and  the  importance  of  the  background  of  organised 
knowledge  may  be  obtained  from  a  study  of  the  decay 
of  memory.  The  more  general  ideas  and  those  earliest 
acquired  are  always  the  last  to  be  lost.  The  aged 
remember  the  events  of  childhood  and  general  prin- 
ciples long  after  recent  events  and  particular  ideas  have 
been  forgotten.  In  brain  diseases  of  different  origins 
the  same  laws  hold.  Common  nouns  are  remembered 
after  proper  names  are  forgotten ;  verbs  are  remembered 
longer  than  nouns ;  and  gestures  persist  when  words  have 
been  forgotten.  The  reason  may  be  found  in  the  greater 
chance  for  the  general  terms  to  grow  into  the  nervous 
system.  The  general  terms  and  general  principles  have 
been  used  hundreds  of  times  where  particular  words  are 
used  once,  and  each  use  makes  the  impression  stronger, 
and  makes  possible  recall  on  new  occasions.  The  same 
factors  that  make  these  fundamental  principles  useful 
and  permanent  in  the  memory  of  the  normal  individual 
make  them  last  to  disappear  with  the  degeneration  of 
nervous  tissue  in  disease  and  old  age. 

Logical  Memory  Is  of  Meaning.  —  Not  only  the 
methods  of  remembering,  but  the  content  of  the  memory 
image,  are  different  in  logical  memory.  One  thinks 
of  remembering  as  a  process  of  reinstating  an  experience 
in  its  original  form.  As  a  matter  of  fact,  however, 
one  does  not  ordinarily  have  the  same  sort  of  image ; 
in  fact,  the  image  may  not  be  at  all  like  the  original ; 
it  merely  means  the  same  thing.  The  image  is  modified 
by  all  that  has  been  seen  in  that  connection  since  the 


LOGICAL   MEMORY  227 

former  experience.  One  nearly  always  remembers  the 
event,  not  as  it  actually  was,  but  as  it  must  have  been 
in  the  light  of  what  has  been  experienced  before  and 
after.  One  interprets  the  experience  in  terms  of  the 
system  of  knowledge,  and  the  system  modifies  the 
images  that  are  recalled.  Reasoning  and  memory 
combine  in  the  construction  of  the  recalled  image. 
Still  more  frequently,  no  very  specific  image  is  reinstated  ; 
one  remembers,  not  the  event  itself,  but  that  the  event 
happened.  The  imagery  involved  in  remembering  that 
a  thing  happened  is  perhaps  some  symbol  of  the  event, 
or  some  general  symbol  plus  the  associations  that  con- 
nect it  with  a  specific  time  ;  the  image  is  lost  in  its  mean- 
ing, in  the  fact  that  it  represents.  The  image  itself  is  not 
attended  to,  and  one  cannot  say,  after  the  experience 
has  been  recalled,  what  the  image  was  in  itself.  This 
sort  of  recall  is  closely  related  to  reasoning,  and  the  pro- 
cess can  be  understood  better  after  the  discussion  of 
meaning  in  the  next  chapter.  Suffice  it  now  to  say  that 
the  memory  is  usually,  not  of  images,  but  of  meanings. 

RECOGNITION 

Forms  of  Recognition.  —  After  recall  conies  recog- 
nition. Recognition  may  be  defined  as  an  awareness 
of  the  time  and  place  of  origin  of  the  memory  image. 
Both  objects  and  ideas  are  recognised,  and  recognised 
in  the  same  way.  One  meets  a  friend  of  earlier  years, 
and  immediately  or  after  some  thought  can  refer  him 
to  a  definite  place  and  to  a  definite  time  in  the  past. 
Similarly  an  idea  may  float  into  memory  and  either  be 
recognised  as  a  fact  read  in  a  school  book,  or  be  referred 


,228  THE  ESSENTIALS   OF  PSYCHOLOGY 

vaguely  to  the  past  without  specific  knowledge  of  its 
warrant  or  of  its  authority.  The  explanation  of  recog- 
nition is  the  same  for  ideas  and  for  objects.  The  process 
can  be  studied  most  easily  in  connection  with  the  delayed 
or  indirect  recognition.  Frequently  one  sees  an  object, 
and  is  at  first  uncertain  where  it  has  been  seen  before 
or  what  it  is.  Gradually  other  ideas  cluster  about  it. 
As  the  new  object  suggests  old  ones,  the  new  begins  to 
seem  familiar,  and  finally  is  completely  recognised. 
Then  it  takes  its  place  with  the  ideas  that  have  them- 
selves been  recognised.  One  may  see  an  animal  and 
feel  that  it  is  of  a  familiar  species,  but  not  remember 
what  it  is.  The  object  suggests  a  setting  in  which  it 
was  seen  before,  and  that  may  suggest  the  name  that 
a  friend  gave  to  it  at  the  time,  or  the  picture  of  the 
animal  in  the  volume  in  which  it  was  looked  up  after  it 
had  been  seen.  A  face  may  be  recognised  in  the  same 
way.  The  face  seems  familiar,  but  the  name  cannot  be 
given  nor  the  place  where  it  was  seen.  Gradually  a 
cluster  of  memories  group  about  the  face,  —  the  back- 
ground of  a  familiar  room  where  the  man  was  seen,  or 
the  class  room  where  he  had  been  sitting ;  then  the  name 
or  other  explanatory  ideas  come  up.  and  recognition  is 
complete.  In  general,  then,  this  delayed  or  mediate 
recognition  is  always  due  to  associates  aroused  by  the 
object  or  idea,  when  it  presents  itself  to  consciousness. 

Mechanism  of  Immediate  Recognition.  —  When 
recognition  is  immediate,  one  knows  at  once  that  the 
object  is  familiar,  there  is  no  evidence  of  the  nature  of 
the  process.  The  idea  or  thing  is  accepted  and  that  is 
all  there  is  to  it.  This  is  the  more  usual  sort  of  recog- 


RECOGNITION  229 

nition.  One  knows  nothing  of  how  a  close  friend  is 
recognised,  or  of  how  one  tells  his  own  text-book  from 
his  neighbour's.  It  is  pretty  clear  from  experiment 
and  observation  that  the  process  is  in  part  the  same 
as  in  mediate  and  delayed  recognition.  Associates 
are  aroused  as  before,  but  they  come  at  once  and  do  not 
attract  attention  for  themselves.  They  give  evidence 
of  their  presence  only  by  the  fact  that  the  object  is 
recognised.  When  the  very  familiar  object  presents 
itself,  there  is  a  rush  of  associates,  or  the  opening  of  a. 
number  of  association  paths  that  bring  the  recognition 
with  them.  To  the  rush  of  associates  one  may  un- 
doubtedly add  a  number  of  movements  called  out 
reflexly.  One  knows  one's  own  fountain-pen  by  the 
fact  that  the  movements  that  it  excites  are  suited  to  trie 
pen  ;  there  is  no  hesitation  or  false  adjustment.  When 
a  friend's  pen  has  been  picked  up  by  mistake,  one  be- 
comes aware  of  the  mistake  by  the  awkwardness  of  the 
movements.  The  position  of  the  fingers,  that  is  best  for 
the  familiar  pen,  makes  the  new  one  scratch,  or  it  fails 
in  some  other  way  to  respond  as  the  old  one  does.  Part 
of  the  recognition  of  an  object  that  is  not  handled  or  that 
does  not  give  rise  directly  to  movements  is  due  to  the 
fact  that  its  uses  are  appreciated,  that  when  it  is  recog- 
nised, one  knows  at  once  what  to  do  with  it  and  how  to 
use  it.  As  a  result  of  the  associates  and  of  the  smooth- 
ness in  the  actual  and  the  intended  or  possible  move- 
ments, the  old  object  ordinarily  arouses  a  feeling  of 
pleasure,  while  the  unfamiliar  is  nearly  always  un- 
pleasant. Possibly  one  may  assume  a  peculiar  feeling 
of  recognition  in  addition  to  the  pleasure,  but  this  is  less 


250        THE  ESSENTIALS  OF  PSYCHOLOGY 

ea:y  to  be  sure  of  than  the  fact  of  recognition.  Three 
factors  contribute  to  the  process  of  recognition.  First, 
the  arousal  of  associates ;  second,  the  excitation  of 
familiar  movements ;  third,  pleasantness,  —  a  result 
of  these  two  processes.  \ 

Recognition  a  Reference  to  the  System  of  Knowledge. 
—  One  question  that  is  at  once  suggested  in  this  con- 
nection is  why  the  arousal  of  old  associates  should  tell 
what  the  object  is  and  where  it  was  seen  before.  Part 
of  the  answer  is  found  in  the  fact  that  the  associates 
themselves  are  recognised.  If  each  associate  must  be 
recognised  by  other  associates,  the  process  would  become 
interminable  and  compel  one  to  run  through  the  ex- 
periences of  the  individual  from  the  time  of  the  event 
recognised  to  the  present  moment.  This  is  evidently 
never  necessary ;  at  most  one  or  two  sets  of  associates 
suffice  for  complete  recognition.  The  reason  is  that 
we  make  use  of  the  system  of  knowledge  in  recognition 
as  in  learning  and  retention.  One  refers  the  new  to  the 
developed  system.  When  the  new  arouses  an  element 
of  this  system,  recognition  is  complete.  In  other  in- 
stances what  we  call  recognition  is  nothing  more  than 
reference  of  the  new  thing  to  a  general  class.  We 
recognise  a  small  animal  as  a  weasel  when  we  can  classify 
it;  there  is  no  implication  that  it  has  ever  been  seen 
before.  This  classification  is  only  a  reference  to  our 
system  of  zoological  knowledge.  Similarly,  prominent 
events  in  life  constitute  a  framework  for  the  recognition 
of  new  events.  These  may  be  the  places  in  which  one 
has  lived,  or  the  different  stages  in  the  school  life  which 
serve  for  the  recognition  of  personal  events  as  do  the 


RECOGNITION  23! 

kings  of  England  as  points  of  reference  for  all  other 
events  of  modern  history,  or  the  succession  of  reigns  in 
Rome  for  ancient  history.  Any  event  is  placed  when 
it  is  known  to  have  been  related  to  or  contemporaneous 
with  one  of  these  landmarks.  To  understand,  and  to 
recognise  in  this  way  are  very  closely  related  operations. 
Each  consists  in  being  referred  to  the  framework  of 
knowledge  or  to  the  system  of  prominent  events. 

Paramnesia.  —  Paramnesia,  an  interesting  illusion  of 
recognition,  throws  much  light  upon  its  nature.  One 
occasionally  feels,  when  in  a  new  place,  that  one  has 
been  there  before.  The  whole  setting  and  many  of  the 
details  of  the  place  are  familiar,  yet  one  is  certain  that 
this  is  the  first  visit.  Plato  described  the  experience 
and  used  it  in  support  of  his  theory  of  the  transmi- 
gration of  souls.  He  argued  that  the  recognition  in- 
dicated that  the  place  had  been  visited  in  an  earlier 
existence.  As  a  matter  of  fact,  however,  the  explanation 
is  to  be  found  in  a  misplaced  recognition.  Some  parts 
of  the  situation  are  similar  to  old  situations.  These 
serve  to  arouse  associates  which  give  rise  to  a  feeling  of 
familiarity,  and  this  feeling  extends  from  the  part  to  the 
whole.  The  illusion  illustrates  the  dependence  of 
recognition  upon  association  and  related  psychological 
processes.  The  old  is  not  recognised  where  these 
processes  are  lacking,  and  the  new  seems  familiar 
when  by  chance  they  are  called  out  where  they  do 
not  belong. 

The  Best  Methods  of  Remembering.  —  Since  the 
ancients  many  attempts  have  been  made  to  find  easy 
and  certain  ways  of  learning  and  remembering,  and  in 


23-2-        THE  ESSENTIALS  OF  PSYCHOLOGY 

all  ages  there  have  been  individuals  who  profess  to 
have  methods  for  improving  the  memory.  All  of  these 
attempt  to  make  use  of  special  methods  in  forming 
associations.  They  fall  into  two  general  classes,  — 
methods  of  learning  single  things  such  as  dates,  and 
methods  of  connecting  two  facts  or  events  that  it  is 
desirable  to  remember  together.  Systems  for  remember- 
ing single  events  attempt  to  connect  them  with  symbols 
that  will  be  more  easily  remembered.  Numbers  are 
remembered  by  representing  each  digit  by  several  con- 
sonants and  then  making  words  that  include  these  con- 
sonants. Thus  one  may  represent  8  by  /,  7  by  g,  and 
i  by  /.  Then  one  can  recall  that  Alfred  came  to  the 
throne  in  871  if  the  burned  cakes  suggest  fagot,  a  symbol 
for  871.  Similar  combinations  could  be  made  to  repre- 
sent any  date  or  number,  and  the  word  is  easier  to  re- 
member than  the  number.  Where  two  events  are  to 
be  connected  in  memory,  it  is  possible  to  form  nonsense 
or  superficial  connections  between  them  that  shall 
serve  to  recall  one  when  the  other  is  given.  In  one 
system  it  is  suggested  that  one  may  remember  that  tele 
in  French  means  '  head/  by  connecting  tete  with  '  po- 
tato ' ;  that  in  turn  with  '  root/  since  potatoes  are 
roots,  and  this  by  contrast  with  '  head.'  Similar  series 
of  words  are  suggested  for  many  other  pairs,  and  the 
system  consists  in  forming  them  for  all  series  of  facts. 
It  is  certain,  however,  that  when  used  extensively,  any 
such  system  requires  more  effort  and  is  less  satisfactory 
than  the  ordinary  means  of  learning.  Mnemonic  verses 
and  similar  devices  have  some  value  in  remembering  a 
few  purely  arbitrary  facts,  such  as  the  number  of  days 


MEMORY   SYSTEMS  233 

in  the  months,  but  the  usefulness  of  the  system  does  not 
extend  far. 

The  best  mnemonic  system  is  the  ordinary  logical 
system  of  classification.  The  connections  are  not  arbi- 
trary here,  and  each  series  of  associates  holds  not  for 
one  fact  alone  but  for  very  many.  In  one  sense,  the 
classifications  of  the  sciences  are  parts  of  a  vast  mne- 
monic system.  Each  general  principle  groups  many 
facts  about  a  single  statement.  Since  the  general  prin- 
ciples are  themselves  more  or  less  closely  connected, 
they  amount  in  practice  to  a  system  of  associations  in 
which  a  few  things,  if  they  are  remembered,  will  serve 
to  recall  all  the  knowledge  of  the  individual.  As  we 
have  seen,  this  system  of  knowledge,  when  it  has  been 
developed,  makes  easier  the  learning  of  all  things  re- 
ferred to  it,  makes  their  retention  more  permanent,  and 
by  giving  them  a  place  assures  their  recognition.  It 
follows  that  the  more  one  knows,  the  better  is  one's 
memory;  the  more  one  knows  of  any  subject,  the 
easier  it  is  to  learn  new  facts  in  that  subject.  Much 
better,  then,  than  any  artificial  memory  system  is  a 
patient,  thorough  learning  and  logical  classification  of 
facts.  This  not  only  makes  easy  the  learning  and  re- 
tention of  the  fact  in  question,  but  prepares  for  the 
acquisition  of  related  facts.  Learning  logically  is  like 
putting  money  at  compound  interest.  The  material  is 
not  only  saved,  but  grows  and  makes  easier  further 
acquisition. 

Summary.  —  Memory,  then,  is  not  a  faculty  but  a 
fact ;  and  on  analysis  it  is  found  to  be,  not  one  fact  or 
process,  but  four  that  together  make  possible  the  re- 


234  THE   ESSENTIALS    OF   PSYCHOLOGY 

instatement  and  use  of  earlier  experiences.  Learning, 
retention,  recall,  and  recognition  are  special  phases  of 
the  laws  of  association,  and  of  the  interaction  between 
the  particular  new  events  and  the  earlier  accumulated 
and  systematised  knowledge.  Although  the  fundamental 
principles  of  memory  are  found  in  the  laws  of  association, 
special  methods  may  be  used  to  advantage  in  learning, 
retention,  and  recall.  But  above  all  special  methods 
stands  the  one  general  principle  that  memory  at  each 
stage  requires  constant  reference  to  systematised  knowl- 
edge. This  makes  learning  easy  and  rapid,  gives  perma- 
nent retention,  assures  recall  on  the  appropriate  occasion, 
and  provides  the  essential  conditions  for  recognition. 

Rules  for  Learning.  —  We  may  summarize  the  re- 
sults of  this  chapter  in  a  series  of  rules  for  study  both 
for  material  to  be  learned  verbatim  and  for  the  ordinary 
retention  of  ideas. 

For  rote  learning : 

1.  Read  over  carefully  the  material  to  be  learned, 
slowly  at  first,  then  more  rapidly  as  it  begins  to  be 
mastered. 

2.  Read  always  with  the  intention  of  remembering 
as  well  as  with  full  attention. 

3.  Attempt  to  repeat  as  soon  as  you  are  confident  of 
success  and  continue  to  repeat  actively  until  the  material 
is  thoroughly  impressed. 

4.  Do  not  attempt  to  learn  all  at  once.     Divide  your 
repetitions.     Repeat  once  a  day,  or  on  alternate  days 
until  mastered. 

5.  Read  the  whole  selection  through  from  beginning 
to  end  rather  than  attempting  to  commit  bit  by  bit. 


RULES   FOR   MEMORY  235 

If  parts  offer  especial  difficulty  you  may  well  depart 
from  this  rule  to  impress  them  separately.  These 
should  be  divided  from  the  rest  by  an  interval  before  and 
after.  Reading  through  the  whole  once  each  day  will 
master  a  selection  of  considerable  length  with  little  effort. 

6.  Rest  for  about  six  minutes  after  learning  one 
selection  before  turning  to  other  mental  work. 

For  learning  ideas  most  of  the  same  rules  may  be 
applied.  In  addition : 

1.  Understand  what  you  read.     To  this  end  (a)  read 
always  with  a  '  why  '  in  mind ;   ask  is  this  so  and  find 
good  reasons  for  or  against  before  you  leave  it.  (6)  Where 
possible  refer  each  fact  to  its  causes,     (c)  Think  over 
what  you  read  in  its  important  connections.     (d)  The 
relations  should  be  represented  graphically  in  a  diagram. 
In  taking  lecture  notes,  write  an  outline  of  the  main 
logical  heads  and  fill  these  in  from  memory  immediately 
afterwards.     Make  a  similar  outline  of  each  chapter 
of  a  book  as  you  read. 

2.  Review  as  frequently  as  possible  to  obtain  the 
value   of    divided    repetitions.     In  reviewing,   diagram 
again  and  bring  out  in  this  review  diagram  the  relation 
between  the  different  lectures  or  lessons. 

3.  Make  as  many  active  responses  as  you  can  during 
the  studying.     Apply  what  you  learn  in  as  many  ways 
as  possible.     Work  problems  that  involve  the  principles. 
If  the  material  permits  draw  the  objects  described. 

4.  On  the  rare  occasions  when  facts  have  no  logical 
connections  you  may  form  arbitrary  or  nonsense  associa- 
tions.    These  should  be  used  as  little  as  possible  and 
then  only  when  they  are  obvious  and  unambiguous. 


236  THE  ESSENTIALS   OF  PSYCHOLOGY 

5.  In  both  forms  of  learning  trust  your  memory  in 
recall.  The  first  suggestion  is  probably  correct  and 
should  be  accepted  unless  you  have  positive  reasons 
against  it.  Confidence  aids  memory,  while  doubt 
paralyzes  recall. 

Imagination.  —  Closely  related  in  many  ways  to 
memory  are  the  processes  grouped  under  the  term 
imagination.  This  term  is  used  in  two  senses,  (i)  It 
designates  the  process  of  forming  images,  the  root  mean- 
ing of  the  term ;  (2)  it  covers  all  processes  of  construc- 
tion, ranging  from  day  dreaming  to  developing  scientific 
hypotheses.  The  first  use  of  the  term  is  approximately 
identical  with  the  formation  of  imagery  discussed  in 
Chapter  V  and  need  not  be  considered  again  here.  The 
second  term  covers  a  wide  field  of  operations  closely 
related  to  memory  and  reasoning  and  in  many  respects 
intermediate  between  them  in  character.  The  ideas 
develop  in  imagination  as  in  memory  under  the  stimu- 
lation of  some  sensory  process  and  run  their  course 
under  the  influence  of  associations.  As  distinguished 
from  memory  the  products  of  imagining  are  not  re- 
instatements of  old  experiences  but  are  new.  This 
does  not  mean  that  the  materials  are'  new.  As  has 
been  repeated  frequently,  all  the  central  processes  are, 
fundamentally,  returned  sensory  experiences.  In  imagi- 
nation, however,  the  materials  are  combined  in  new 
ways  and  thus  make  new  objects  or  events. 

The  Course  of  Imagination.  —  The  same  laws  of 
association  are  apparent  in  imagination  as  in  memory. 
The  only  difference  is  that  an  element  from  one  experience 
recalls  a  similar  element  from  another,  or  events  that 


IMAGINATION  237 

were  contiguous  or  succeeded  each  other  in  one  expe- 
rience are  transferred  to  other  larger  connections  by 
virtue  of  common  elements.  In  most  constructions  of 
the  imagination,  one  may  distinguish  two  factors,  the 
functions  of  which  correspond  to  recall  and  recognition 
in  memory,  the  production  and  testing,  respectively. 
The  associative  processes  are  constantly  active,  mental 
pictures  occupy  the  entire  waking  life,  but  it  is  only 
now  and  again  that  the  constructions  are  of  value.  It 
is  not  possible  to  obtain  a  particular  effect  directly. 
Usually  a  number  of  constructions  will  appear  before 
one  presents  itself  which  fulfils  the  requirements  and 
wins  approval.  The  acceptance  or  rejection  alone  can 
be  controlled ;  what  shall  appear  is  subject  only  to  the 
most  general  control.  That  one  cannot  even  think  of 
a»new  thing  at  will  is  made  evident  by  attempting  to 
draw  as  many  different  figures  as  possible.  When  ex- 
amined all  show  many  of  the  same  characteristics, — 
one  element  runs  through  them  all.  While  a  desire 
for  one  idea  will  nearly  always  induce  something  of 
the  same  class,  more  exact  control  is  impossible,  —  one 
can  only  wait  for  the  desired  construction  to  turn  up 
and  it  may  come  soon  or  late  or  never. 

Forms  of  Imagination.  —  The  products  of  imagination 
may  be  more  or  less  like  objects  and  events  actually 
experienced..  It  is  customary  to  distinguish  between 
reproductive  and  productive  imagination.  The  pro- 
ductive imagination  gives  material  that  is  very  different 
from  anything  seen  before,  reproductive  is  more  like 
memory.  The  difference  is  one  of  degree  only  and  no 
great  agreement  can  be  obtained  as  to  what  is  produc- 


238  THE  ESSENTIALS   OF   PSYCHOLOGY 

tive  and  what  reproductive.  It  is  said  that  Sir  Walter 
Scott  carefully  examined  even  the  minuter  flowers  in  a 
setting  that  he  had  chosen  as  the  scene  of  one  of  his 
romances  thus  taking  much  of  what  was  to  be  a  new 
construction  from  direct  and  detailed  observation.  This 
would  certainly  be  reproductive  imagination  in  spite  of 
the  newness  of  the  events  depicted.  At  the  other  ex- 
treme are  certain  descriptions  of  poetic  fancy,  Dante's 
Inferno  for  example,  or  the  constructions  of  the  mathe- 
matician or  inventor.  One  approximates  memory,  the 
other  reason.  They  differ  in  the  attitude  taken  toward 
the  product  rather  than  in  the  product  itself  or  the  way 
in  which  it  is  attained. 

QUESTIONS 

1.  How  much  of  the  accuracy  of  the  testimony  concerning  ar 
accident  depends  upon  attention  and  perception  and  how  much 
upon  memory? 

2.  What  is  the  difference  in  the  activities  involved  in  observa- 
tional and  in  rote  memory  ? 

3.  Is  learning  ever  perfect?    Is  forgetting  ever  complete? 
What  is  the  difference  between  learning  half  and  half  learning? 

4.  What  is  the  '  setting '  process  in  learning  ?    How  does  it  ex- 
plain the  advantages  of  divided  repetitions? 

5.  What  is  retroactive  inhibition?    how  dependent  upon  the 
perseveration  tendency? 

6.  Why  is  cramming  a  bad  method  of  study?    Answer  in  the 
light  of  the  laws  of  learning  and  forgetting. 

7.  What  rules  should  be  observed  in  studying  to  make  probable 
a  satisfactory  recitation? 

8.  How  does  the  ordinary  recitation  by  question  and  answer 
illustrate  the  laws  of  recall?    What  is  the  question  and  what  the 
answer  in  the  terminology  of  memory  ?     Give  some  conditions  that 


MEMORY   AND   IMAGINATION  239 

may  make  a  good  recitation  impossible,  even  if  the  answer  to  the 
question  is  known. 

9.  Cite  instances  from  your  own  experience  of  associative  and 
reproductive  inhibition. 

10.  What  are  some  of  the  advantages  of  forgetting  ? 

11.  Give  instances  in  your  own  experience  that  illustrate  the 
advantages  of  logical  over  rote  memory.     In  what  subjects  do 
you  use  the  first  and  in  which  the  second  ? 

12.  Trace  the  course  of  recognition  in  some  instance  in  which 
recognition  is  delayed.     Why  should  the  mental  operations  that 
result  make  the  object  seem  familiar  ? 

13.  What  rules  suggest  themselves  for  acquiring  a  good  mem- 
ory ?    What  are  the  limitations  of  the  rules  ? 

EXERCISES 

1.  Show  a  group  of  students  a  picture  with  a  few  prominent 
highly  coloured  figures.     Twenty  minutes  to  an  hour  later  ask  the 
members  to  describe  it  in  detail.     Prepare  a  list  of  questions 
to  bring  out  important  points  and  request  them  to  answer  them. 
Count  the  number  of  objects  that  can  be  readily  seen  and  find  the 
proportion  of  these  reported  by  each  subject.     What  percentage 
of  objects  reported  are  not  in  the  picture  or  are  wrongly  described  ? 
Make  a  similar  count  of  the  questions  rightly  answered. 

2.  Select  two  bits  of  verse  of  eight  lines  each  as  much  alike  as 
possible  in  metre,  ease  of  learning,  etc.     Learn  one  at  one  sitting, 
keeping  a  record  of  the  number  of  repetitions  and  the  time  required 
for  learning.     Read  the  second  through  twice  each  day  until  it  is 
learned.     Which  method  is  the  more  economical? 

3.  Choose  two  other  selections  of  eight  lines.     Learn  the  first  as 
you  naturally  would,  or  two  lines  at  a  time.     Learn  the  second  by 
reading  through  from  beginning  to  end.     Compare  the  two  results 
for  the  time  and  number  of  repetitions  required.     Unless  the  selec- 
tions are  well  chosen,  it  may  be  necessary  to  repeat  the  experiment 
several  times  and  average  before  positive  results  are  obtained. 

4.  Relearn   after   twenty-four    hours   one    of    the   selections 
learned  for  exercise  3.     Relearn  another  originally  learned  by  th« 


240  THE   ESSENTIALS   OF   PSYCHOLOGY 

same  method  after  forty-eight  hours.  Compare  the  number  of 
repetitions  required  for  relearning  each  with  the  number  required 
for  the  original  learning.  How  can  you  use  the  results  as  a 
measure  of  retention  or  of  forgetting? 

REFERENCES 

WATT  :  Economy  of  Memory. 

COLVIN  :  The  Learning  Process. 

JAMES  :  Principles  of  Psychology,  vol.  i,  ch.  xvi. 

PILLSBURY  :  Attention,  chapter  ix. 

TITCHENER  :  Text-book  of  Psychology,  pp.  403-427. 

MEUMANN  :  The  Psychology  of  Learning. 


CHAPTER  IX 
REASONING 

REASONING  has  always  been  given  a  very  prominent 
place  among  mental  operations.  To  be  able  to  reason 
is  generally  recognised  as  the  mark  of  a  high  degree  of 
intelligence,  and  to  reason  well  is  one  of  the  most  certain 
marks  of  exceptional  mental  development.  The  effec- 
tiveness of  a  man's  reasoning  measures  in  large  degree 
his  value  to  society,  and  his  own  possibilities  of  success. 
It  has  frequently  been  said  that  reason  is  peculiarly  a 
human  endowment.  Wundt,  for  example,  asserts  that 
animals  never  reason  and  man  seldom.  If  reasoning 
occupies  this  high  place  in  the  scale  of  human  capacities, 
it  is  evidently  desirable  to  know  what  distinguishes  it 
from  the  other  mental  operations  and  so  far  as  is  possible 
to  determine  the  laws  that  make  for  accurate  and  true 
reasoning.  The  definitions  of  reasoning  show  much  di- 
versity. A  very  simple  definition  is  that  reasoning  is 
purposive  thinking.  But  to  constitute  reasoning,  think- 
ing must  be  not  only  purposive,  i.e.  must  have  a  definite 
end,  but  must  also  be  true  and  be  able  to  justify  itself. 
Reasoning  is  a  process  of  solving  problems.  The  solution 
of  the  problem  must  be  true,  and  must  also  be  proved  true. 
To  define  reasoning  fully,  it  must  be  distinguished  from 
imagination  and  memory  when  observed  from  the  inside, 
and  from  instinct  and  habit  when  expressed  in  action. 

B  241 


242  THE   ESSENTIALS   OF   PSYCHOLOGY 

Reasoning  Distinguished  from  Other  Mental  Processes. 
—  Reasoning  may  be  distinguished  from  memory  and 
imagination,  not  so  much  by  the  character  of  the  mental 
states  or  by  the  way  they  are  obtained,  as  by  the  atti- 
tude taken  toward  them  when  they  arise.  The  idea 
attained  by  reasoning  may  be  exactly  like  an  idea  which 
on  other  occasions  is  merely  remembered.  The  laws 
that  govern  the  appearance  of  rational  ideas  are  the 
laws  of  association,  controlled  in  the  same  way  as  in 
memory  or  imagination.  The  three  processes  are  differ- 
ent in  that  the  results  of  reasoning  are  new  and  are  ac- 
cepted as  true ;  the  results  of  memory  are  true,  but  not 
new;  and  the  results  of  imagination  are  new,  but  not 
true.  Belief  is  the  acceptance  of  a  construction  as  true, 
and  may  be  said  to  hold  the  same  relation  to  reasoning 
that  recognition  does  to  memory.  When  an  idea  is 
recognised  and  believed,  it  is  remembered ;  when  be- 
lieved, but  not  recognised,  it  is  the  result  of  reasoning; 
and  when  neither  recognised  nor  believed,  it  is  imagined. 
The  distinction  between  memory  and  reason  may  be 
illustrated  by  the  different  ways  of  preparing  a  lesson 
in  geometry.  One  student  merely  commits  the  demon- 
strations to  memory  and  when  called  upon  to  recite 
repeats  by  rote  the  words  of  the  book.  Another  does 
not  commit  to  memory  but  reads  over  and  understands 
each  point  made.  When  called  upon  to  recite,  he  works 
out  the  problem  for  himself  in  large  measure,  following 
only  the  general  lines  of  the  book.  He  has  made,  not 
the  words,  but  the  ideas  his  own  and  is  able  to  make 
new  applications  of  the  method  when  called  upon  to  do 
so.  He  believes  in  his  result  because  he  can  see  that 


HABIT  AND  REASONING  243 

it  fits  in  with  the  other  propositions  he  has  learned  and 
with  other  things  that  he  knows,  but  he  does  not  recog- 
nise the  conclusion  or  the  construction  when  it  develops 
in  his  mind. 

Objective  Criteria  of  Reasoning.  —  If  one  were  watch- 
ing the  actions  of  a  man  or  animal  and  knew  nothing  of 
the  thinking  processes  behind  them,  one  would  still 
decide  on  certain  occasions  that  the  individual  was 
reasoning,  and  on  other  occasions  that  he  was  acting 
from  habit  or  instinct,  or  from  mere  chance  responses. 
As  compared  with  habit  or  instinct,  reasoned  actions 
must  be  new,  —  this  must  be  the  first  occasion  on  which 
the  movement  has  been  made:  as  opposed  to  mere 
chance  response,  the  reasoned  movement  is  repeated 
unfailingly,  and  is  not  preceded  by  other  responses. 
Lloyd  Morgan  illustrates  the  difference  by  the  way  his 
dog  learned  to  carry  a  stick  through  a  picket  fence. 
His  habits  and  instinct  led  him  to  pick  it  up  by  the 
middle.  Of  course  it  caught  at  both  ends  on  the  pickets. 
Only  after  many  trials  did  he  happen  to  hit  upon  seizing 
it  by  the  end  and  thus  succeed  in  dragging  it  through. 
If  he  had  reasoned,  he  would  have  appreciated  the  im- 
possibility of  his  first  attempt  without  trial,  or  at  the 
first  trial.  The  trials  would  have  been  made  in  thought 
only,  and  action  would  not  have  been  attempted  until 
the  problem  had  been  solved  mentally.  Then  one  act 
would  have  been  all  that  was  necessary.  Possibly,  one 
would  accept  as  reasoning  an  act  that  gives  an  adequate 
solution  of  a  new  problem,  when  no  solution  in  thought 
preceded  the  act.  On  this  the  definitions  divide.  If 
one  does  include  acts  of  this  sort  under  reasoning,  it 


244        THE  ESSENTIALS  OF  PSYCHOLOGY 

would  follow  that  animals  reason ;  if  reasoning  is  always 
a  matter  of  thought  or  first  a  matter  of  thought,  then 
reasoning  cannot  with  certainty  be  ascribed  to  animals, 
i  Reasoning  Involves  Proof.  —  One  further  step  is  often 
present  in  reasoning  and  by  some  is  made  essential  to 
the  definition.  This  is  justifying  the  conclusion  before 
it  has  been  tried  in  practice.  This  is  certainly  not 
present  in  animals  and  most  of  what  is  ordinarily  called 
reasoning  in  man  has  no  explicit  justification.  Reason- 
ing has  also  been  restricted  to  thinking  in  general  terms. 
While  much  of  human  reasoning  is  general,  it  would 
unwarrantably  limit  the  term  to  exclude  all  instances  of 
solving  particular  problems.  If  we  bring  together  the 
characteristics  of  reasoning,  we  may  say  that  it  is  a 
mental  operation  that  (i)  is  directed  to  the  solution 
of  a  problem,  is  purposive,  not  random ;  (2)  the  results 
of  the  thinking  must  be  a  new  solution  that  is  accepted 
as  true ;  (3)  the  action  to  which  the  thinking  leads  must 
also  be  new  and  immediately  adequate ;  (4)  the  solution 
may  be  warranted,  in  advance  of  test,  by  reference  to 
general  principles  or  earlier  experiences;  and  (5)  the 
solution  itself  may  be  general,  i.e.  applicable  to  many 
situations,  or  it  may  be  particular.  The  two  most  im- 
portant new  principles  to  be  discussed  in  connection 
with  reasoning  are  the  nature  of  belief  or  proof,  and 
thinking  in  general  terms. 

Belief  the  Test  of  Truth.  —  The  simplest  answer  to 
the  question,  what  is  true,  is  that  anything  is  true  for 
the  individual  which  he  is  willing  or  able  to  believe. 
The  simplest  answer  to  the  question,  what  can  he  be- 
lieve, is  that  he  believes  anything  that  is  in  full  harmony 


MEANING  245 

with  his  experience.  Ordinarily  there  is  immediate  re- 
jection of  any  statement  that  is  not  consistent  with  one's 
previous  experience.  Just  as  the  normal  man  rejects  an 
hallucinatory  impression  because  it  contradicts  the  con- 
ditions of  his  seeing  and  will  not  fit  into  his  idea  of  the 
world,  so  a  statement  or  conclusion  out  of  harmony  with 
the  earlier  knowledge  is  refused  belief.  The  general 
rule  is  that  one  believes  when  there  is  no  reason  to  doubt, 
when  there  is  no  conflict  between  new  and  old.  The 
older  experiences  stand  guard  in  the  reasoning  operations 
as  in  all  mental  operations,  and  when  any  construction 
does  not  agree  with  them,  the  unpleasant  feeling  of 
doubt  arises  as  a  bar  to  its  acceptance.  Many  con- 
structions pass  without  question,  but  when  one  is 
doubted,  it  must  then  be  formally  proved  or  given  up 
as  untrue.  Doubt  is  the  incentive  to  all  of  the  formal 
reasoning  processes,  while  belief  makes  them  unneces- 
sary. 

Meaning  and  the  Concept.  —  One  of  the  most  striking 
facts  in  connection  with  reasoning  is  that  the  images 
employed  are  not  important  for  themselves,  but  only 
for  their  meaning,  for  the  things  that  they  represent. 
In  a  demonstration  in  geometry,  for  example,  the  figure 
represents  all  objects  of  similar  form,  without  reference 
to  their  size  or  the  materials  from  which  they  are  made. 
The  statements  will  hold  of  pieces  of  paper  or  tracts  of 
land,  just  as  truly  as  of  the  figure  drawn  in  chalk  or 
pencil.  In  all  reasoning  the  same  phenomenon  -is  ob- 
served. When  one  plans  a  house,  one  thinks  of  lumber 
and  of  stone,  but  not  of  any  particular  boards  or  stones ; 
or,  if  one  does  think  of  a  particular  material,  it  is  recog- 


246        THE  ESSENTIALS  OF  PSYCHOLOGY 

nised  that  anything  else  of  the  sort  may  be  substituted 
for  it  without  injury  to  the  plans.  The  image  in  ques- 
tion does  duty  for  or  represents  all  other  articles  of  the 
same  kind.  An  image  used  in  this  way  to  represent 
several  things  is  called  a  concept,  and  the  things  that 
it  represents  at  the  moment  constitute  its  meaning. 
Two  questions  naturally  arise  with  reference  to  this 
representative  function,  (i)  How  is  it  possible  for  a 
single  concrete  image  to  represent  so  many  different 
objects  in  thought?  This  is  the  problem  of  meaning. 
(2)  What  is  the  character  of  the  imagery  that  represents 
the  numerous  particulars?  This  is  the  historical  prob- 
lem of  the  nature  of  the  concept. 

Meaning  Involves  the  Principles  of  Recognition.  — 
The  representative  function  of  images  is  more  closely 
related  to  the  function  of  recognition  than  to  any  of  the 
other  principles  hitherto  discussed.  When  an  object  is 
perceived,  it  takes  its  value  from  the  earlier  connections 
in  which  it  has  been  seen.  If  the  object  is  not  at  once 
recognised,  it  will  ordinarily  soon  recall  other  objects 
that  are  familiar.  The  process  of  recognition  was  seen 
to  be  due  in  last  analysis  to  these  partially  or  completely 
aroused  associations.  When  the  object  is  not  recog- 
nised as  a  particular  object  or  as  an  object  that  has 
been  seen  in  some  particular  place,  it  may  still  be  appre- 
ciated as  a  member  of  a  class.  I  recognise  a  bird  in 
flight  as  a  robin,  but  not  as  the  robin  that  has  its  nest 
on  my  lawn ;  I  recognise  a  tool  as  a  hammer,  but  not 
as  my  hammer  that  has  been  missing  since  last  week. 
This  class  recognition  is  sometimes  called  cognition, 
but  it  follows  the  same  general  laws  as  recognition.  It, 


THE   CONCEPT  247 

too,  is  dependent  in  part  upon  the  connections  that 
have  been  formed  between  many  objects  and  one  single 
name  or  type,  and  in  part  upon  the  arousal  of  old  situa- 
tions in  which  similar  objects  have  been  experienced, 
and  of  old  uses  to  which  they  have  been  put.  These 
associates  prepare  one  to  deal  with  the  object  when 
presented,  and  give  it  a  peculiar  conscious  quality,  a 
quality  that  changes  with  its  classification. 

The  representative  function  of  the  image  has  the  same 
explanation.  When  the  image  presents  itself,  it  has  a 
constellation  of  potential  associations  about  it  and  these 
give  it  meaning.  These  connections  tend  to  recall  each 
of  the  objects  represented  and  the  uses  to  which  each 
has  been  put.  These  association  paths,  partly  aroused, 
make  the  image  representative  of  each  object  and  of 
each  use  intended.  When  it  represents  a  single  object, 
there  is  only  one  associate  or  group  of  associates ;  when 
it  represents  a  class,  many  associates  are  partially 
aroused.  The  feeling  varies  with  the  associates.  Think- 
ing goes  on  as  if  all  the  associates  were  in  consciousness; 
instead  of  the  single  representative  image.  As  the 
recognition  of  the  object  depends  upon  the  associates 
that  are  partially  aroused  at  the  moment,  so  the  mean- 
ing of  the  image  is  the  expression  of  its  partially  or 
potentially  aroused  connections.  When  one  recognises 
a  man  as  a  man,  the  same  paths  are  aroused  as  when 
one  has  in  mind  a  particular  image  of  a  man  and  knows 
that  it  represents  all  men  of  whatever  kind. 

The  Concept.  —  The  image  that  represents  the  par- 
ticulars, the  image  that  has  the  meaning,  is  known  as 
the  concept.  The  nature  of  the  concept  has  been  much 


248        THE  ESSENTIALS  OF  PSYCHOLOGY 

discussed  in  the  history  of  philosophy  and  psychology. 
It  has  been  argued  that  the  image,  which  has  a  general 
meaning,  must  itself  be  general  in  form.  Following  out 
this  line  of  reasoning,  it  has  been  asserted  that  the 
image  of  general  meaning  may  be  some  bare  outline 
of  all  the  particulars  that  it  represents,  or  that  it  may 
be  a  composite  picture  of  all.  My  image  of  a  dog  would 
be  a  dog  without  colour  or  particular  size  or  length  of 
hair.  My  image  of  a  man,  a  composite  photograph  of 
all  the  men  I  had  ever  seen.  In  any  case  it  would  be 
an  image  that  was  like  each  of  the  things  it  represents, 
but  not  identical  with  any  of  them.  This  sort  of  vague 
schematic  image  sometimes  constitutes  the  concept,  but 
it  is  not  at  all  universal.  It  is  no  more  necessary  that 
the  concept  be  represented  by  a  general  image,  than 
that  the  object  recognised  as  some  sort  of  tool  shall  be 
general  in  form.  What  gives  each  its  generality  is  the 
group  of  associates  that  cluster  about  it.  In  fact, 
the  two  most  usual  images  of  general  meaning  are,  on 
the  one  hand,  an  individual  object  that  has  nothing  of  the 
general  in  its  make-up ;  on  the  other  hand,  the  word, 
which  is  not  at  all  like  any  of  the  things  represented. 
When  one  thinks  man  in  general,  one  is  likely  to  think 
either  of  some  familiar  individual,  or  merely  the  word 
man.  Each  will  represent  perfectly  all  men  or  all  human 
qualities,  since  what  is  important  is  not  the  imagery, 
but  the  associates  that  are  aroused. 

The  individual  image  represents  the  different  particu- 
lars in  the  same  way  that  a  model  represents  the  different 
machines  that  may  be  manufactured  under  a  patent. 
The  model  may  be  of  wood,  while  the  machines  are 


THE   CONCEPT  249 

made  of  different  metals;  the  model  is  usually  small, 
the  actual  machines  are  large;  and  numerous  other 
changes  may  be  made  in  the  model,  but  it  still  is  re- 
garded as  typical  of  them.  Its  meaning,  like  the  mean- 
ing of  the  concept,  is  found  in  all  of  the  machines  that 
might  be  built  on  its  lines.  The  model  and  the  actual 
machines  are  often  spoken  of  as  embodying  the  same 
idea,  in  spite  of  the  differences  in  size  and  materials. 
When  thus  associated  with  many  particulars,  an  in- 
dividual idea  stands  for  them  in  thought,  and  the  results 
of  the  thinking  hold  true  for  each  of  the  particulars 
represented,  as  well  as  for  the  actual  image.  The  word, 
too,  represents  objects  in  thinking  because  of  its  many 
associates.  When  the  word  is  thought,  the  associates 
are  aroused  and  colour  the  word,  so  that  it  seems  to  be 
not  a  mere  word,  but  something  much  more  real  and 
vivid.  The  difference  between  the  word  as  bare  image 
and  as  representative  of  objects  has  been  illustrated  by 
James  by  asking  one  to  stare  at  a  word  on  the  printed 
page  for  a  few  minutes  as  just  a  word.  After  one  has 
looked  at  the  word  in  this  way  for  a  short  time,  the 
meanings  seem  to  drop  away  and  the  word  image  alone 
remains.  The  difference  between  this  and  the  word 
as  ordinarily  used  is  very  striking,  how  striking  one 
can  discover  only  by  trying  the  experiment.  In  gen- 
eral, then,  the  image  that  is  the  centre  of  the  concept 
is  relatively  a  matter  of  indifference;  the  associates 
of  the  image  are  essential.  The  meaning  of  the  con- 
cept changes  from  moment  to  moment  as  the  connections 
change.  Words  change  their  meanings  with  the  context. 
The  English  '  son  '  and  the  French  son  have  an  alto- 


250  THE   ESSENTIALS   OF   PSYCHOLOGY 

gether  different  feeling.  The  reason  is  that  the  partially 
active  associates  change  as  the  context  changes.  Every- 
thing serves  to  emphasise  the  fact  that  the  associates 
which  irradiate  from  the  concept  are  the  important 
part,  and  the  image  from  which  they  irradiate  is  rela- 
tively indifferent. 

The  Development  of  Concepts.  —  The  statement 
that  the  meaning  of  the  concept  depends  upon  the 
associates  that  have  been  formed  about  it  is  well  illus- 
trated by  the  way  concepts  grow,  either  in  the  individ- 
ual, or  in  the  development  of  knowledge  as  a  whole. 
The  child's  knowledge  grows  through  a  process  of 
developing  and  changing  concepts.  If  one  dare  specu- 
late on  the  nature  of  the  first  experiences  of  the  child, 
it  would  seem  that  in  the  beginning  all  is  chaos.  It  is 
only  as  concepts  develop,  about  which  the  experiences 
may  cluster  and  to  which  they  may  be  referred,  that 
any  order  is  introduced.  When,  for  example,  a  child 
sees  a  kitten  for  the  first  time,  it  has  no  meaning  for 
him.  It  is  a  mass  of  sensations,  that  is  all.  Even 
what  little  appreciation  there  is,  is  in  terms  of  older 
experiences  that  have  become  definitely  established. 
The  kitten  resembles  the  mother's  furs,  its  colour 
suggests  coal ;  each  of  its  other  qualities,  if  they  are 
appreciated  at  all,  are  appreciated  only  as  they  are 
referred  to  known  qualities  and  objects.  When  the 
kitten  has  been  seen  a  few  times,  it  becomes  in  its  turn 
a  centre  of  reference  for  new  experiences.  At  first  it 
stands  as  the  type  for  all  animals;  the  first  dog  seen 
is  called  '  kitty  '  and  any  other  animal  receives  the 
same  greeting.  The  concept  of  the  cat  develops  from 


THE   CONCEPT  25 1 

this  point  in  two  ways.  Each  new  kind  of  cat  will 
increase  the  number  of  objects  represented  by  the 
term,  while  each  quality  of  the  cat,  or  of  any  cat,  will 
increase  the  qualities  that  may  be  ascribed  to  the  ani- 
mal. When  the  animal  is  seen  to  eat,  a  new  point  of 
resemblance  to  man  is  indicated.  As  the  college  stu- 
dent studies  the  anatomy  and  physiology  of  the  cat, 
the  concept  is  deepened  and  extended  through  the  re- 
lations that  are  found  between  less  fully  developed 
animals,  on  the  one  side,  and  chemical  and  physical 
laws,  on  the  other.  Each  of  these  experiences,  either 
of  new  sorts  of  cats  or  of  new  qualities  and  responses 
of  cats,  serves  to  extend  the  concept.  These  individ- 
uals and  laws  and  functions  are  all  represented  by  the 
concept  in  thinking;  and  the  greater  the  number  of 
connections  that  have  been  developed  with  it,  the 
wider  is  the  concept,  because  the  greater  is  the  number 
of  associates  that  are  partially  aroused  when  the  image 
is  called  to  mind.  The  concept  is  the  point  of  reference 
of  all  that  is  known  about  cats. 

The  development  of  concepts  in  the  race  is  even  more 
interesting,  and  the  development  can  be  traced  more 
completely.  One  of  the  most  used  is  the  system  of 
numbers.  As  the  word  '  digit '  shows,  counting  was 
at  first  always  on  the  fingers.  The  larger  groups,  five 
and  ten,  are  the  fingers  of  one  hand  and  of  two,  respec- 
tively. Still  larger  numbers  are  multiples  of  ten,  the 
largest  number  that  can  be  counted  on  the  fingers. 
After  the  habit  of  referring  objects  to  the  fingers  in 
counting  had  been  developed,  the  reference  became 
less  explicit,  and  finally  all  thought  of  the  fingers  was 


252  THE   ESSENTIALS   OF  PSYCHOLOGY 

lost  from  the  number  idea.  The  number  symbols  de- 
veloped and  were  capable  of  replacing  the  finger  idea 
altogether.  One  may  still  see  some  evidence  of  the 
fingers  in  the  Roman  numerals,  but  in  the  Arabic  sym- 
bols in  ordinary  use,  there  is  now  no  evidence  of  any 
similarity  to  the  fingers  or  to  anything  that  at  all  corre- 
sponds to  the  values  that  are  represented.  The  num- 
bers gathered  many  associates,  and  each  new  sort  of 
thing  counted  served  to  make  the  concept  more  general 
in  its  application,  until  the  original  reference  and  prac- 
tically all  imagery  disappeared  in  the  meaning  or  idea. 
One  can  trace  similar  stages  in  the  development  of  any 
sort  of  concept.  Words  of  abstract  meaning  were 
nearly  all  concrete  at  one  time.  The  meaning  first 
became  very  much  extended ;  then  some  one  meaning, 
remote  from  the  original,  became  emphasised,  and  the 
original  one  was  forgotten,  or  what  was  originally  the 
name  of  a  substance  or  thing  came  to  designate  an 
abstract  quality.  Each  of  the  fundamental  ideas  of 
science  could  probably  be  traced  to  some  perfectly 
concrete  object  or  idea  that  had  been  applied  succes- 
sively to  many  objects  and  so  gradually  lost  all  par- 
ticular meaning.  General  notions  like  atom,  molecule, 
ether,  and  force,  have  undoubtedly  developed  in  this  way. 
Now  they  are  concepts  that  have  value  because  they 
represent  a  large  number  of  particular  experiences. 

Knowledge  a  System  of  Concepts.  —  Laying  aside 
for  the  moment  the  problem  of  the  development  of  the 
concept,  one  may  assert  that  practically  all  of  the  ordered 
knowledge  of  any  individual  is  a  system  of  concepts. 
The  system  of  concepts  contains  not  merely  abstract  and 


THE   CONCEPT  253 

concrete  things  like  atoms  and  ether,  tables  and  trees, 
but  general  laws  and  principles,  such  as  special  laws  of 
connections  and  the  principle  of  cause  and  effect.  All 
that  one  knows  finds  its  place  in  the  system  of  concepts ; 
the  system  of  knowledge  and  the  system  of  concepts  are 
practically  identical  terms.  These  concepts  and  gen- 
eral laws  have  value,  (i)  because  they  are  types  and  are 
in  consequence  more  nearly  true  than  any  particular 
experience  of  the  class ;  (2)  they  represent  a  mass  of 
particulars  by  virtue  of  the  fact  that  each  of  the  par- 
ticulars has  been  associated  with  the  concept,  and, 
without  detriment  to  the  truth  of  any  statement  that 
is  made,  might  be  replaced  by  any  one  of  the  particulars. 
This  system  of  concepts  is  an  essential  factor  in  each 
of  the  simpler  psychological  operations,  as  well  as  in 
reasoning.  One  ordinarily  sees,  not  the  group  of  sen- 
sations, but  the  developed  type  or  concept  of  the  object. 
Similarly  any  statement  or  thing  can  be  remembered 
much  more  easily  if  only  it  can  be  connected  with  the 
system  of  knowledge  already  obtained.  Ordinarily  one 
recognises  an  object  by  referring  it  to  the  class  to  which 
it  belongs,  even  when  it  may  be  recognised  also  as  a 
particular  member  of  the  class.  While  concepts  play 
an  enormously  important  part  in  each  of  these  mental 
operations,  it  is  in  reasoning  that  the  concept  attracts 
most  attention.  Here  its  importance  cannot  be  over- 
stated. Each  of  the  reasoning  operations  involves 
reference  to  the  system  of  concepts.  The  situation  is 
judged  by  referring  it  to  the  system  of  knowledge,  and 
to  its  particular  concept.  When  a  solution  has  been 
reached,  it  is  justified  or  proved  by  a  reference  to  the 


254        THE  ESSENTIALS  OF  PSYCHOLOGY 

appropriate  general  concept,  law,  or  principle.  All 
processes  of  understanding  and  of  proof  are  in  terms 
of  the  classified  body  of  knowledge,  concepts. 

The  Stages  of  Reasoning.  —  We  have  seen  that  the 
reasoning  operation  is  ordinarily  some  bit  of  purposive 
thinking  of  which  the  conclusions  are  capable  of  proof. 
Reasoning  comes  when  one  has  a  purpose  and  is  thwarted 
in  that  purpose.  One  has  no  incentive  to  accomplish- 
ment if  one  has  no  purpose,  and  no  new  operations  are 
demanded  if  the  old  habits  are  sufficient  to  effect  the 
purpose.  Reasoning  presupposes  a  thwarted  purpose 
as  its  starting  point.  Three  stages  in  the  reasoning 
operation  may  be  distinguished.  First,  the  obstacle 
must  be  appreciated  or  understood ;  second,  some  plan 
that  will  remove  the  obstacle  must  be  developed ;  and 
third,  the  plan  that  suggests  itself  must  be  proved, 
must  be  justified.  The  obstacle  may  block  the  prog- 
ress, either  of  thought  or  action.  But  if  the  obstacle 
be  to  thought  alone,  it  will  probably  be  an  obstacle  to 
action  at  some  time,  and  to  remove  it  in  thought  will 
make  action  easier  when  occasion  arises.  The  first  of 
these  steps,  the  process  of  understanding  the  difficulty, 
is  judgment ;  the  second  is  inference ;  and  the  third, 
proof. 

One  may  illustrate  the  different  parts  of  the  process 
by  any  simple  problem.  Suppose  two  boys  are  canoe- 
ing, and  it  is  desired  to  reach  a  distant  place  in  a  limited 
time.  Suddenly  the  canoe  scrapes  hard  on  a  rock.  A 
moment  later  water  begins  to  rise  in  the  bottom.  At 
first  it  is  a  question  whether  there  is  a  leak  or  whether 
the  water  has  been  shipped.  As  it  increases  in  amount, 


PHASES   OF   REASONING  255 

it  becomes  evident  that  the  water  comes  from  a  leak. 
When  this  is  decided  upon,  one  has  a  judgment,  a  classi- 
fication or  interpretation  of  the  trouble.  Further  ex- 
planation comes  when  the  scraping  on  the  rock  is  recalled, 
and  a  complete  understanding  is  obtained  when  the 
canoe  is  turned  up  and  the  hole  through  the  canvas  is 
discovered.  The  next  step  is  to  decide  upon  a  remedy. 
Someone  suggests  that  a  patch  might  be  made  of  a 
handkerchief.  This  is  probably  rejected  as  soon  as  the 
thinness  of  the  material  is  recalled.  A  second  or  added 
suggestion,  that  the  handkerchief  be  covered  with  pitch 
from  a  spruce  tree  on  the  shore,  is  accepted  by  both  and 
put  to  the  test.  Thinking  of  coating  the  handkerchief 
with  pitch  constitutes  the  inference.  Were  the  sugges- 
tion of  using  pitch  questioned  by  one,  and  successfully 
defended  by  the  other,  the  process  would  be  completed 
in  proof.  Proof  comes  only  when  there  is  preliminary 
doubt  on  the  part  of  the  man  who  makes  the  suggestion, 
or  on  the  part  of  someone  who  hears  it.  Ordinarily 
the  suggestion  will  be  accepted  without  question.  It 
will  be  believed  at  once  and  at  once  be  put  into  practice. 
It  is  only  when  there  is  doubt  before  the  test  is  made 
that  one  requires  proof,  and  the  full  reasoning  process 
is  completed.  In  our  case,  one  would  justify  the  use 
of  pitch  on  the  handkerchief  only  when  someone  asks 
how  that  would  help.  Then  the  justification  may  be 
made  in  one  of  several  ways.  One  may  answer  in  the 
abstract  that  pitch  is  sticky  and  waterproof,  or  one 
may  recall  that  the  Indians  used  pitch  in  repairing  or 
making  canoes,  or  one  may  recall  his  own  use  of  pitch 
for  some  similar  purpose. 


256  THE   ESSENTIALS   OF   PSYCHOLOGY 

The  Judgment.  —  Of  these  steps  in  the  reasoning 
process,  judgment  and  the  different  forms  of  proof  have 
received  the  most  attention,  particularly  from  the 
logician.  The  judgment  may  be  denned  most  simply 
as  the  process  of  referring  a  new  situation  to  its  appro- 
priate concept,  or,  as  it  is  more  usually  denned,  as  the 
process  of  '  ascribing  meaning  to  the  given/  Each 
difficulty  or  obstacle  has  a  different  class  in  which  it 
belongs ;  it  is  understood  in  terms  of  a  typical  older  ex- 
perience, or  group  of  older  experiences,  which  usually 
has  been  named.  When  anything  is  understood  it  is 
referred  to  a  familiar  class  or  object,  and  this  reference, 
in  a  sense,  transfers  the  meaning  of  the  old  to  the  new. 
Each  difficulty  or  obstacle  has  a  class  in  which  it  belongs 
and  when  it  is  referred  to  that  class  it  is  in  a  fair  way  to 
be  solved  or  overcome.  At  least  the  first  step  has  been 
taken  towards  overcoming  it.  When  an  army  engineer 
has  been  assigned  the  task  of  bridging  a  river,  he  must 
first  measure  and  so  classify  the  various  features  of  the 
obstacle,  must  measure  the  width  of  the  stream,  the 
depth  of  the  water,  and  appreciate  the  particular  dangers 
to  which  the  place  is  exposed.  Each  measurement  is  in 
essentials  a  reference  of  the  new  situation  to  a  familiar 
class.  When  he  classifies  it  in  this  way,  he  is  ready  to 
solve  the  problems,  he  knows  what  lengths  of  material  to 
order  and  what  type  of  bridge  to  construct. 

Classes  of  Judgments. — We  arrange  judgments  them- 
selves in  classes  or  groups.  For  our  purposes,  they 
must  themselves  be  judged.  All  are  alike  in  that  they 
refer  the  material  or  situation  to  be  understood  to  its 
class,  but  the  classes  themselves  differ  widely.  The 


JUDGMENT  257 

object  may  be  referred  to  its  class  as  a  thing.  This  is 
the  simplest.  Where  two  things  are  present  that  differ 
in  any  way,  one  may  compare  them  as  greater  or  less 
in  each  of  the  respects  in  which  they  differ,  as  to  weight 
or  length  or  breadth.  This  judgment  of  comparison 
is  like  the  ordinary  judgment  in  that  the  relation  is 
referred  to  some  typical  relation  of  greater  or  less  in 
each  respect.  Although  comparison  involves  two  ob- 
jects, the  comparison  itself  is  a  single  process  and  con- 
sists in  referring  the  particular  difference  to  some  stand- 
ard difference  or  typical  relation.  The  judgment  of 
evaluation  is  the  form  most  frequently  used  in  every- 
day life.  In  this  the  object  to  be  judged  is  referred  to 
a  scale  of  values  or  excellencies  which  an  individual  has 
acquired  in  the  course  of  his  experience.  We  judge  all 
commodities  with  reference  to  their  monetary  value 
when  buying  them.  We  judge  people  with  reference 
to  their  intelligence,  their  morals,  their  agreeableness, 
and  the  probability  that  they  will  succeed.  All  of 
these  judgments  are  made  by  assigning  the  particular 
specimen  to  the  point  in  the  scale  where  he  or  it  belongs. 
The  standards  are  not  usually  definitely  pictured.  The 
one  who  judges  may  not  even  know  that  he  has  them 
until  called  upon  to  judge.  The  procedure  prescribed 
by  the  army  personnel  board  for  grading  officers  asked 
the  judges  to  think  of  five  men  who  represented  the 
best,  the  worst,  the  average  and  one  midway  between 
in  each  of  the  qualities  to  be  judged  and  then  to  grade 
the  man  to  be  judged  by  saying  which  man  he  most 
resembles.  This  made  the  scale  of  standards  fully 
conscious.  Evaluation  probably  gave  the  name  to 


258        THE  ESSENTIALS  OF  PSYCHOLOGY 

the  whole  process,  as  it  is  what  the  judge  does  in 
criminal  cases.  He  must  first  classify  the  crime  and 
then  decide  on  the  severity  of  the  offence  in  the  scale 
of  offences  and  assign  a  punishment  accordingly. 

The  Verbal  Judgment.  —  In  what  has  been  regarded 
as  the  typical  judgment  by  the  formal  logician,  the 
process  of  reference  is  expressed  in  words.  The  form 
of  expression  is  undoubtedly  more  variable  than  the 
formal  logician  will  admit.  In  many  cases,  perhaps  in 
most  cases,  the  new  situation  is  represented  in  the  sub- 
ject of  the  sentence  or  the  proposition,  and  the  general 
concept  or  principle  to  which  it  is  referred  is  put  in  the 
predicate.  When  the  water  is  seen  to  appear  in  the 
bottom  of  the  canoe,  one  would  say  '  there  is  a  leak/ 
in  which  the  *  there  '  represents  the  general  situation ; 
the  '  leak/  the  classification  of  the  situation  or  difficulty. 
The  particular  present  experience  is  stated  in  the  sub- 
ject; the  concept  that  interprets  it,  in  the  predicate. 
Under  the  head  of  judgment  are  included,  not  only 
these  interpretations  of  the  present  situations,  but  also 
many  possible  experiences  that  may  need  to  be  faced 
for  the  benefit  of  later  action  and  disposition.  Such 
are  all  of  the  descriptions  and  classifications  of  science, 
and  all  abstract  explanations  whatever.  From  one 
point  of  view  this  text  on  psychology  may  be  said  to 
be  nothing  more  than  a  series  of  references  of  the  mental 
phenomena  to  classes  and  laws  that  may  enable  one  to 
know  what  to  expect  in  the  future,  and  to  understand 
the  thinking  of  the  present  and  of  the  past.  All  under- 
standing is  a  reference  of  the  thing  to  be  understood  to 
the  system  of  concepts;  the  thing  to  be  understood  is 


INFERENCE  259 

ordinarily  represented  in  speech  by  the  subject  of  the 
judgment  or  of  the  sentence,  and  the  concept  by  which 
it  is  explained  is  expressed  in  the  predicate.  What 
for  the  psychologist  is  a  reference  of  the  new  to  a  con- 
cept is,  for  formal  logic  and  grammar,  a  combination 
of  words,  a  succession  of  subject  and  predicate. 

Inference.  —  Inference  is  primarily  a  psychological 
process.  Ordinarily  one  solves  problems  by  casting 
around  until  the  proper  solution  suggests  itself.  The 
suggestion  follows  laws  of  association,  just  as  does 
memory  or  imagination,  but  the  essence  of  the  reason- 
ing or  inference  is  to  be  found,  not  so  much  in  the  way 
the  suggestions  come  up  as  in  the  way  they  are  treated 
when  they  come.  The  greater  the  fluidity  of  ideas,  the 
greater  the  number  of  suggestions  that  arise,  the  more 
likely  it  is  that  the  true  solution  of  the  problem  will  be 
obtained.  The  essential  thing  is  that  the  true  solution 
be  recognised  when  it  appears,  and  that  all  false  sugges- 
tions be  rejected.  If  the  reader  will  observe  his  think- 
ing while  trying  to  solve  a  problem  in  geometry,  or 
while  trying  to  find  some  way  to  earn  money  for  a 
vacation,  or  in  any  other  problem,  he  will  see  that 
many  different  suggestions  present  themselves  before 
one  is  found  that  is  accepted  as  a  probable  solution. 
The  problem  of  inference,  then,  falls  into  two  distinct 
parts:  first,  how  do  the  suggestions  arise?  second,  how 
are  the  true  suggestions  separated  from  the  false?  The 
answer  to  the  first  question  has  been  given  in  the  chapter 
on  association.  The  solution  in  reasoning  is  reached 
through  the  connections  that  have  been  earlier  estab- 
lished, is  controlled  and  directed  by  the  purpose  of  the 


260  THE   ESSENTIALS   OF   PSYCHOLOGY 

moment,  the  mental  context.  The  more  important 
second  process,  the  acceptance  or  rejection  of  the  solu- 
tions offered,  is  an  expression  of  belief.  When  a  sug- 
gestion in  harmony  with  all  that  is  known  on  the  subject 
comes,  it  is  ordinarily  accepted  and  put  to  practical  test. 
When  a  suggestion  does  not  harmonise  with  some  ex- 
perience in  consciousness  at  the  moment,  it  is  imme- 
.diately  rejected.  When  the  response  is  in  doubt,  one 
must  proceed  to  proof  of  some  sort  before  either  accept- 
ing or  rejecting.  It  should  be  emphasised,  however, 
that  in  very  many  cases  no  formal  proof  is  necessary. 
When  a  suggestion  is  believed,  it  is  at  once  acted  upon 
without  any  preliminary  proof.  The  outcome  of  the 
;action  is  the  only  test  required. 

Proof.  —  The  process  that  has  most  concerned  the 
logician  is  proof.  In  its  essentials,  the  process  of  prov- 
ing a  statement  or  conclusion  is  one  of  producing  belief 
in  the  mind  of  the  thinker  himself  or  of  a  companion. 
Doubt  is  necessary  to  call  forth  proof.  The  forms  of 
proof  are  ordinarily  divided  into  deductive  and  induc- 
tive. Deductive  proof  gives  belief  by  referring  the 
conclusion  that  is  in  doubt  to  some  general  principle 
or  law  already  accepted.  The  new  receives  added 
credence  from  the  old.  Induction  draws  the  justifica- 
tion for  the  conclusion  from  specific  earlier  experiences 
or  from  experiment. 

The  Syllogism.  —  The  most  familiar  form  of  de- 
duction is  the  syllogism.  In  the  syllogism,  the  general 
principle  by  which  the  conclusion  is  justified  is  ordi- 
narily stated  first;  then  the  conclusion  is  referred  to 
that  general  principle;  and,  finally,  the  conclusion  to 


THE   SYLLOGISM  261 

be  established  is  stated.  It  may  be  illustrated  in  '  All 
metals  conduct  electricity :  tungsten  is  a  metal,  there- 
fore tungsten  conducts  electricity.'  It  should  be  as- 
serted explicitly  that  the  order  of  thinking  is  not  the 
order  of  the  syllogism,  but  that  the  conclusion  presents 
itself  first,  and  the  rest  of  the  syllogism  is  then  developed 
to  justify  the  conclusion.  One  would  never  make  a 
series  of  statements  of  the  sort,  unless  one  had  started 
to  use  tungsten  to  close  an  electric  circuit  and  someone 
had  questioned  its  value.  The  syllogism  in  practice  is 
advanced  to  prove  the  conclusion,  and  develops  after 
the  conclusion  has  been  hit  upon  and  questioned;  the 
conclusion  does  not  grow  out  of  the  major  premise.  In 
actual  everyday  thinking  the  syllogism  seldom  makes  its 
appearance.  The  conclusions  ordinarily  are  rejected  or 
accepted  immediately,  and  no  justification  is  required. 
When  it  does  appear,  it  is  usually  expressed  in  a  much 
abbreviated  form.  In  the  example  given,  one  would 
say  merely,  '  tungsten  is  a  metal,  you  know  ' ;  and  this 
would  suffice  to  suggest  all  that  is  important  in  the 
syllogism. 

One  question  that  might  be  raised  is,  why  does  the 
syllogism  or  the  mention  of  the  major  premise  con- 
stitute proof?  The  answer  is  that  it  serves  to  connect 
the  conclusion  with  the  system  of  concepts  or  general 
principles  previously  accepted.  When  one  sees  that  the 
new  suggestion  comes  under  the  old  principles,  the 
belief  that  has  been  developed  for  the  system  of  knowl- 
edge extends  to  the  particular  instance.  When  estab- 
lished and  accepted  laws  and  principles  are  connected 
with  the  conclusion,  doubt  disappears.  The  process  of 


262        THE  ESSENTIALS  OF  PSYCHOLOGY 

reference  to  the  system  of  knowledge,  not  merely  justifies 
the  old,  but  also  increases  the  number  of  applications 
of  the  old.  Each  doubt  that  is  resolved  increases  the 
belief  in  the  principle,  since  it  assures  its  connection 
with  a  new  fact.  It  extends  its  application,  and  when 
the  conclusion  itself  is  confirmed  in  practice,  the  general 
principle  receives  new  warrant. 

Proof  by  Induction.  —  The  second  form  of  proof, 
induction,  consists  in  reference  of  the  suggestion  to  the 
particular  earlier  experiences.  When  questioned  about 
tungsten,  one  would  not  reply  that  it  is  a  metal,  but 
would  point  to  an  electric  lamp,  or  recall  some  other 
instance  in  which  it  is  known  that  tungsten  wire  has 
been  used  in  electrical  work.  Or  one  might  take  the 
still  more  empirical  course  of  actually  testing  to  see 
whether  it  does  conduct,  and  whether  the  resistance  is 
low  enough  to  make  it  useful  in  the  particular  applica- 
tion. It  is  probable  that  the  proof  from  induction  is 
much  more  closely  related  to  the  proof  by  deduction, 
than  was  assumed  of  old.  The  particular  instances,  by 
which  the  conclusion  is  justified,  must  be  in  some  degree 
typical  or  they  will  be  valueless.  If  the  tungsten  used 
before  was  mixed  with  some  other  metal,  it  might  very 
well  be  that  the  results  that  held  of  that  sample  would 
not  hold  here.  Unless  again  it  is  assumed  that  laws 
hold  universally,  no  conclusion  can  be  drawn  from  any 
number  of  particular  cases.  Each  new  case  would 
needs  be  studied  for  itself  and  the  results  of  one  ex- 
perience could  not  be  applied  to  a  later  case.  Again, 
as  has  been  seen,  older  developed  concepts  are  involved 
in  any  perception,  so  that  in  each  of  the  particular  ob- 


PROOF  263 

servations  principles,  similar  in  kind  to  the  general 
principles  that  warrant  the  conclusion  in  the  syllogism, 
must  have  been  used.  On  the  other  hand,  there  is 
always  more  or  less  implicit  reference  to  particular 
experiences  in  the  general  principles  that  justify  the 
conclusion  in  the  syllogism.  The  difference  between  the 
two  sorts  of  proof  is  one  of  emphasis  only;  the  same 
fundamental  principles  are  involved  in  each.  In  any 
case  proof  is  found  in  a  reference  to  experience.  In 
one  case  the  experience  is  formulated  in  concepts  and 
the  general  is  emphasised;  in  the  other  the  particular 
experiences  are  in  the  foreground,  the  general  laws  only 
implied. 

Analogy.  —  Perhaps  the  form  of  proof  most  used  in 
popular  discussions  is  analogy.  It  involves  something 
of  the  principles  of  each  of  the  more  formal  types,  in- 
duction and  deduction.  Analogy  consists  in  pointing 
out  the  similarities  between  the  statement  to  be  proved 
and  others  with  which  the  man  to  be  convinced  is 
familiar  and  which  he  is  willing  to  accept.  Thus,  one 
argues  that  a  man  should  invest  in  a  new  company  by 
mentioning  companies  in  the  same  line  that  have  suc- 
ceeded. One  argues  that  it  is  possible  to  communicate 
thought  without  words,  written  or  spoken  by  mention- 
ing wireless  telegraphy.  Analogy  is  a  satisfactory  form 
of  proof,  provided  only  that  the  similarity  is  in  essen- 
tials. Too  often  the  resemblances  are  in  non-essentials 
and  the  proof  is  seeming,  not  real.  Thus  the  argument 
for  the  new  stock  is  likely  to  say  nothing  of  the  relative 
financial  standing  of  the  two  companies  and  attempts 
no  comparison  of  the  probable  earnings.  The  argument 


264        THE  ESSENTIALS  OF  PSYCHOLOGY 

for  telepathy  or  thought  transference  without  words 
neglects  to  mention  the  lack  of  transmitting  or  receiving 
apparatus.  Where  analogies  are  critically  drawn,  they 
approximate  the  validity  of  the  syllogism;  where  the 
resemblances  are  only  superficial,  they  may  be  com- 
pletely misleading. 

Summary.  —  In  brief  outline,  reasoning  consists  in 
solving  problems,  and  in  justifying  the  solution  when 
it  is  obtained.  The  occasion  for  the  reasoning  is  always 
a  thwarted  purpose.  The  first  step  in  the  solution  is 
to  understand  the  nature  of  the  check,  and  this  is  ac- 
complished by  referring  the  present  difficulty  to  some 
old  principle,  to  some  old  concept.  The  second  step  is 
to  obtain  a  solution.  This  is  provided  by  the  laws  of 
association.  Finally,  this  solution  must  be  justified 
when  questioned.  The  justification  is,  ordinarily, 
through  reference  of  the  suggested  solution  to  the 
system  of  earlier  knowledge,  to  the  system  of  concepts. 
The  whole  process  of  inference  is  thus  a  series  of  inter- 
actions between  the  new  and  the  old  and  ordered  ex- 
periences. The  old  is  constantly  giving  order  and 
warrant  to  the  new,  while  on  their  side  the  new  are 
constantly  extending  and  correcting  the  old  experiences. 

QUESTIONS 

1.  How  may  reasoning,  memory,  and  imagination  be  distin- 
guished?   Habit  and  reasoning? 

2.  What  gives  an  image  meaning?    What  makes  an  idea  a 
concept? 

3.  How  does  your  abstract  idea  of  a  triangle  differ  from  your 
memory  of  a  particular  triangle  ?    How  do  you  picture  to  yourself 
'machine'  as  a  general  term?    Describe  the  mental  content  fully. 


REASONING  265 

4.  Can  you  trace  in  your  own  experience,  or  in  the  experience  of 
some  child  you  know,  the  growth  and  extension  of  meaning  that  a 
concept  like  force  has  undergone? 

5.  Enumerate  five  abstract  terms  in  English  which  bear  evi- 
dence  of  the  development  of  the  corresponding  concept  from  » 
concrete  experience. 

6.  How  is  a  science  a  system  of  concepts?    How  does  such  a 
system  develop  ? 

7.  Outline  the  steps  in  a  reasoning  operation. 

8.  Illustrate  the  three  more  important  forms  of  judgment :  of 
things ;  of  relations ;  of  values. 

9.  What  do  you  mean  when  you  say  that  you  understand  a 
mechanical  toy?    What  does  seeing  your  way  out  of  an  involved 
situation  imply?    How  is  the  process  related  to  judgment  as  it  is 
defined  in  the  text  ? 

10.  How  is   inference  related   to  action?    What  place  has 
association  in  inference  ? 

11.  When  do  we  prove  a  conclusion ?    How  do  you  prove  any 
conclusion  or  statement  ? 

12.  Distinguish  inductive  from  deductive  proof.    How  are 
they  related  ? 

1 3 .  How  do  you  know  when  the  solution  of  a  problem  is  correct  ? 
How  can  you  demonstrate  its  correctness  to  another? 

EXERCISES 

1.  Stare  at  the  word  triangle  for  a  minute  by  measurement 
and  keep  a  record  of  the  changes  the  word  goes  through  during  that 
time.     Explain  the  result. 

2.  Prepare  two  weights  of  10  and  10^  grams  by  loading  empty 
cartridge  shells  with  shot.    Have  an  assistant  lift  first  one  and 
then  another  and  judge  which  is  heavier.    What  is  the  process? 
Does  a  type  play  any  part  ?  . 

3.  Try  to  work  out  an  original  device  of  a  simple  sort ;  e.g.  find 
a  substitute  for  a  stairway  in  your  dwelling.    Record  each  step  in 
the  mental  operation.    Can  you  state  the  process  in  a  single 
word? 


266  THE   ESSENTIALS    OF   PSYCHOLOGY 

REFERENCES 

PILLSBURY  :  The  Psychology  of  Reasoning. 

ANGELL  :  Psychology,  chs.  x,  xi,  xii. 

DEWEY  :  How  We  Think. 

TITCHENER  :  Text-book  of  Psychology,  pp.  5°5-5°7' 


CHAPTER  X 
INSTINCT 

Instinct  and  Experience.  —  One  might  conceivably 
treat  man  as  an  altogether  passive,  intellectual  creature 
whose  mental  life  is  restricted  to  calm  contemplation, 
and  whose  contemplation  can  be  explained  in  terms  of 
sensations  and  memories,  and  combinations  and  selec- 
tions from  sensations  and  memories.  So  far  we  have 
been  emphasising  this  phase  but  it  is  far  from  being 
the  whole  story.  To  complete  our  description  we  must 
add  a  discussion  of  the  active  and  feeling  side  of  con- 
sciousness. Fundamental  to  an  understanding  of  either 
action  or  feeling  is  a  consideration  of  the  different  innate 
tendencies  of  the  individual.  These  are  his  instincts. 
Man  is  constantly  acting,  not  only  in  the  light  of  his 
own  experience  and  learning,  but  also  in  terms  of  various 
innate  tendencies.  They  have  an  even  more  profound 
influence  on  the  development  of  both  feelings  and  ac- 
tions. All  through  life  they  serve  as  a  background  for 
the  acquired  capacities,  and  they  colour  feeling  and 
determine  action.  They  often  conflict  with  the  ac- 
quired and  explicit  knowledge  where  that  knowledge 
has  been  fully  developed. 

Signs  of  Instinct.  —  Instincts  may  be  detected  in  two 
ways.  First,  the  organism  at  birth  exhibits  certain  re- 
sponses that  cannot  have  been  learned.  These  responses 
267 


268  THE   ESSENTIALS   OF   PSYCHOLOGY 

show  a  very  marked  similarity  in  all  infants.  The  babe 
expresses  his  disapproval  of  the  first  discomfort  to  which 
he  is  subjected  by  a  violent  outcry.  He  responds  to 
the  first  opportunity  for  nourishment  with  the  appro- 
priate sucking  movements.  All  of  the  immediate  ne- 
cessities of  life  are  provided  for  by  instinctive  responses. 
Second,  in  the  adult  life  there  are  many  responses  and 
feelings  that  cannot  be  explained  by  experience,  that 
are  in  fact  out  of  harmony  with  experience.  These 
arise  spontaneously  and  take  approximately  the  same 
form  in  all  individuals,  although  they  need  not  have 
been  present  at  birth.  Under  this  head  come  the  tend- 
encies to  self-assertion,  the  bashfulness  of  the  adolescent 
youth,  many  fears,  together  with  a  host  of  movements 
not  learned  in  advance  of  their  execution.  Instincts, 
then,  fall  into  two  classes.  They  are  movements  that 
are  made  at  birth  or  are  movements  that  show  them- 
selves relatively  late  in  life,  but  which  need  no  pre- 
liminary learning  or  practice.  While  the  term  is  used 
most  frequently  in  connection  with  movements,  instinct 
also  explains  much  of  feeling  and  many  of  the  intellectual 
processes.  The  disagreeableness  of  bitter  and  the  pleas- 
antness of  sweet  can  no  more  be  understood  from  the 
experience  of  the  individual  than  the  blushing  of  the 
maiden  or  the  cry  of  the  child.  Fear,  too,  is  at  once  a 
movement  or  a  series  of  movements,  and  a  conscious 
state.  Under  instincts  we  shall  consider  explicitly  or 
implicitly  both  actions  and  feelings. 

The  Physiology  of  Instinctive  Acts.  —  We  may  under- 
stand the  fundamental  nature  of  instincts  best  if  we 
consider  what  must  be  the  inherited  characteristic.  If 


BIOLOGY   OF   INSTINCT  269 

we  turn  back  to  our  discussion  of  nervous  physiology, 
it  is  evident  that  these  movements  must  have  a  basis 
in  the  nervous  system  at  birth.  The  part  of  the  nervous 
system  to  which  we  must  look  for  an  explanation  is 
the  synapse,  the  point  of  connection  between  nerve- 
cells.  We  know  that,  when  a  habit  is  formed,  there  is 
some  lessening  of  the  resistance  offered  by  the  synapse 
to  the  transmission  of  the  nervous  excitation.  In  habit, 
the  lessened  resistance  is  due  to  frequent  early  connec- 
tion. Since  instincts  present  themselves  at  birth,  the 
openness  of  the  synapses  must  be  inherited.  In  brief, 
instincts  must  be  due  to  something  physical.  This 
physical  characteristic  is  to  be  found  in  open  connec- 
tions between  sensory  and  motor  neurones.  When 
the  stimulus  presents  itself,  the  movement  that  con- 
stitutes the  instinct  is  at  once  evoked.  How  feelings  are 
transmitted  is  an  unsettled  question,  but  it  is  probable 
that  part  of  the  instinctive  feeling  is  due  to  instinctive 
motor  responses.  Whether  there  are  other  predisposi- 
tions to  response  involved  in  the  dislike  of  bitter,  for 
example,  is  as  yet  unknown. 

The  Origin  of  Instincts.  —  Instincts  are  immediately 
explained  by  the  inheritance  of  predispositions  to  re- 
sponse, the  inheritance  of  open  connections  between 
sensory  and  motor  neurones.  The  next  problem  that 
suggests  itself  is  how  these  connections  originated. 
This  problem,  like  the  problem  of  inheritance  above, 
is  entirely  a  biological  one.  Two  explanations  have 
been  given  of  the  origin  of  instincts.  The  simpler 
is  that  instincts  are  merely  inherited  habits.  On  this 
theory  some  ancestor  learned  a  movement,  and  the 


270        THE  ESSENTIALS  OF  PSYCHOLOGY 

habit  was  transmitted  to  his  descendants  and  became 
a  racial  possession.  Were  the  biologist  willing  to 
accept  this  theory,  the  explanation  of  the  origin  of 
instincts  would  be  very  simple.  Unfortunately  the  evi- 
dence that  a  change  wrought  in  one  individual  is  trans- 
mitted to  his  offspring  is  not  accepted  by  the  great 
majority  of  biologists.  Weismann  has  demonstrated 
to  the  satisfaction  of  many  of  his  colleagues  that  the 
structures  of  the  body  are  so  completely  set  off  from  the 
tissues  which  are  to  continue  the  race  that  the  changes  in 
the  body  have  no  influence  upon  the  inheritance  of  the 
offspring.  The  cells  from  which  the  progeny  are  to 
develop  have  in  potentiality  at  the  birth  of  the  individual 
all  the  characteristics  that  they  later  reveal,  —  they  are 
influenced  only  by  the  factors  that  weaken  or  destroy  the 
body  as  a  whole.  Whatever  be  the  outcome  of  the  bio- 
logical controversy,  it  is  necessary  for  the  psychologist 
to  construct  a  theory  of  instinct  on  the  assumption  of 
the  accepted  biological  theory. 

Instinct  a  Product  of  Natural  Selection.  —  On  this 
theory  of  Weismann,  instincts  come  not  through  a 
change  in  the  habits  of  the  individual,  but  through 
some  chance  change  in  the  characteristics  of  the  germ 
plasm.  It  is  a  fact  that,  while  the  characteristics  of 
the  parent  are  transmitted,  they  are  not  transmitted 
accurately,  there  is  always  variation  in  the  characters. 
If  one  sows  a  thousand  seeds  from  the  same  plant,  the 
young  plants  will  show  a  wide  range  of  variation  from 
the  parent  plant  and  from  each  other.  The  theory 
of  the  development  of  instincts  assumes  this  same  tend- 
ency to  variation  in  the  nervous  system  and  in  the 


BIOLOGY   OF   INSTINCT  271 

instincts  that  correspond  to  the  nervous  connections. 
If  this  known  fact  of  variation  be  accepted,  all  that  is 
necessary  for  the  development  of  an  instinct  is  that 
some  selection  be  made  from  the  variations.  This 
selecting  agent  has  been  found  by  all  the  evolutionary 
theories  hi  the  environment.  When  a  variation  in  re- 
sponse better  suited  to  the  environment  than  the  older 
responses  makes  its  appearance,  the  animal  that  shows 
the  variation  will  be  more  likely  to  survive.  If  this 
variation  is  inherited,  as  it  tends  to  be,  the  offspring 
of  this  animal  will  survive  in  greater  numbers  and  in 
time  will  outnumber  those  with  less  adequate  responses. 
In  brief,  variations  in  responses  are  constantly  appear- 
ing as  the  result  of  changes  in  the  structure  of  the  germ 
plasm.  The  animal  that  has  the  more  beneficial  re- 
sponses will  live  and  its  offspring  will  increase,  while 
any  animal  that  develops  variations  unsuited  to  the 
environment  will  be  destroyed,  or  the  offspring  will 
be  fewer.  As  a  result  of  this  variation  in  structure 
and  response,  with  selection  of  the  animals  that  show 
suitable  variations,  instincts  become  constantly  more 
suited  to  the  conditions  of  life,  and  also  become  more 
and  more  complicated.  Variation  and  selection  can 
account  for  any  instinct,  granted  only  a  sufficiently 
long  time  for  the  variation  to  develop. 

Suppose,  for  example,  that  we  have  a  large  number  of 
rudimentary  organisms  with  all  possible  combinations 
of  two  responses.  Assume,  e.  g.  that  certain  organisms 
in  the  mass  seek  food  and  flee  dangers,  that  others 
flee  from  food  and  seek  the  dangerous  stimulus,  that 
a  third  class  flee  from  both  food  and  the  dangerous  stim- 


272        THE  ESSENTIALS  OF  PSYCHOLOGY 

ulus,  while  the  fourth  seek  both.  Of  the  entire  group 
only  the  first  class  will  long  survive,  the  others  will  either 
starve  to  death  or  be  eliminated  by  approach  to  danger- 
ous stimuli  or  organisms.  Each  variation  of  the  primary 
responses  in  the  progeny  will  lead  to  similar  elimination, 
or,  as  the  responses  become  more  numerous  and  more 
adequate,  a  greater  proportion  of  the  generation  will 
survive.  In  time,  we  would  have  a  set  of  instincts  that 
would  serve  to  protect  the  organisms  from  the  more 
evident  and  usual  dangers.  The  whole  process  of  devel- 
opment of  instincts  is  thus  due  to  the  development  of 
the  physical  structures  upon  which  these  responses 
depend.  But  it  does  not  follow  that  instincts  are  neces- 
sarily simple.  Many  instincts  even  of  comparatively 
low  animals  are  extremely  complex.  The  egg-laying 
instinct  of  the  Yucca  moth,  cited  by  Lloyd  Morgan,  is 
a  case  in  point.  The  eggs  of  the  moth  are  always  laid 
in  the  seed  pod  of  the  Yucca  plant,  and  after  they  are 
deposited,  pollen  is  gathered  and  placed  in  the  hollow 
pistil  and  fertilises  the  seeds.  It  is  a  movement  that 
could  never  have  been  learned  and  the  moth  can  have 
no  idea  of  its  purpose,  for  the  moth  dies  at  once  after  the 
process  is  completed.  The  continuance  of  the  species 
of  both  the  moth  and  the  plant  depends  altogether  upon 
the  accurate  performance  of  the  act.  The  larvae  when 
they  hatch  need  the  developing  seeds  for  food ;  the  seeds 
of  the  plant  would  not  be  fertilised  and  consequently 
would  not  develop  without  the  aid  of  the  insect.  In 
such  a  case  the  instinct  has  all  the  outward  signs  of 
intelligence,  but  must  have  developed  without  the  aid 
of  intelligence. 


CLASSIFICATION    OF    INSTINCTS  273 

Forms  of  Human  Instincts.  —  While  instincts  are 
more  striking  in  animals  and,  in  the  lower  forms,  are 
more  easily  distinguished  in  animals,  they  are  very 
numerous  and  important  in  man.  Professor  James 
asserts  that  man  has  more  instincts  than  any  other 
animal.  A  complete  list  would  require  too  much 
space,  but  it  will  prove  profitable  to  enumerate  the 
more  important  classes  with  some  of  the  more  striking 
instances  under  each  head.  Instincts  may  be  conven- 
iently classified  as  individual,  racial,  and  social.  Indi- 
vidual instincts  make  for  the  welfare  of  the  agent,  racial 
for  the  continuance  of  the  species,  and  social  for  the 
preservation  of  the  group  or  society.  It  is  not  always 
possible  to  draw  a  sharp  line  between  classes,  but  the 
broader  lines  of  distinction  are  clearly  marked. 

Individual  Instincts.  —  Among  the  individual  instincts, 
we  may  distinguish  those  that  care  for  the  essential 
movements  of  the  child.  Here  come  in  order  the  vocal 
protests  against  discomfort,  the  early  and  later  move- 
ments of  taking  nourishment,  the  movements  of  self- 
protection,  the  early  locomotor  movements.  Under 
this  head  fall  all  the  simple  movements  that  the  child 
is  called  upon  to  make  to  meet  the  demands  of  the 
environment.  Many  of  them  are  not  pure  instincts 
or  do  not  long  remain  pure.  An  instinct  may  lead  to 
an  awkward  or  vague  movement,  but  when,  as  is  usual, 
the  movement  is  improved  in  performance  by  some 
chance  variation  in  its  character,  that  desirable  varia- 
tion is  likely  to  take  the  place  of  the  original  movement. 
Probably  in  most  of  the  later  movements,  habit  and 
instinct  are  inextricably  confused.  Whether  learning 


274        THE  ESSENTIALS  OF  PSYCHOLOGY 

to  walk,  for  example,  is  altogether  an  instinct  or  not 
is  still  an  open  question.  Most  likely  it  has  an  instinc- 
tive basis,  as  is  shown  by  the  alternate  movement  of 
the  feet  of  an  infant  when  they  are  lightly  stimulated, 
but  a  very  large  part  of  the  development  is  due  to  habit 
formation.  Instinct  and  habit  cooperate  in  this  as  in 
many  of  the  other  simpler  acts. 

Another  striking  group  of  the  individualistic  instincts 
may  be  seen  in  the  fears.  Every  child  and  many  adults 
evidence  fears  that  could  not  have  been  derived  through 
experience  and  many  that  are  in  direct  opposition  to 
knowledge.  The  infant  shows  a  constant  succession 
of  fears  that  appear,  last  for  a  few  days  or  months,  and 
then  disappear,  to  be  replaced  by  others.  Fear  of 
moving  things,  fear  of  living  things  or  of  soft  things, 
fear  of  the  dark,  fear  of  men  alone  or  of  women  alone, 
of  children  but  not  of  adults,  run  their  course  one  after 
another  in  the  first  few  years  of  the  life  of  the  child. 
They  seem  to  appear  without  reason  and  to  vanish 
equally  without  reason.  If  the  fear  is  confirmed,  it 
may  persist  for  a  long  time ;  if  groundless,  it  will  ordi- 
narily vanish  as  quickly  and  as  unexpectedly  as  it  came. 
Apparently  each  fear  is  the  concomitant  of  a  certain  stage 
hi  the  ripening  of  the  nervous  system.  When  the  right 
stage  appears,  the  instinct  shows  itself;  when  that 
period  of  organic  transition  passes,  the  instinct  goes. 
Certain  instinctive  fears  persist  into  adult  life.  Here 
one  has  the  fear  of  high  places,  the  fear  of  reptiles 
and  other  small  animals,  the  fear  of  death  and  of  the 
dead,  fear  of  the  strange  and  unexplained,  including  the 
supernatural.  These  fears  are  probably  present  in  some 


CLASSIFICATION   OF   INSTINCTS  275 

degree  in  all  individuals  whose  daily  life  has  not  forced 
them  into  frequent  contact  with  the  source.  One  may 
assert  lack  of  fear,  one  may  even  feel  that  the  fear  is 
absurd  and  unintelligible,  but  when  occasion  arises,  the 
proper  response  makes  its  appearance.  One  may  assert 
boldly,  even  haughtily,  an  entire  disbelief  in  ghosts  and 
the  supernatural,  but  not  be  able  to  pass  through  a 
cemetery  alone  at  midnight  without  feeling  in  some 
slight  degree  uncomfortable,  unless,  of  course,  such 
promenades  have  been  frequent.  Again  one  cannot 
hold  the  finger  relaxed  against  the  glass  of  a  cage  while 
a  rattlesnake  strikes  at  it,  and  that  in  spite  of  positive 
assurance  that  no  harm  can  come  from  the  act. 

In  the  third  class  of  individualistic  instincts  one  finds 
a  large  group  of  activities  with  a  wider  social  reference. 
Under  this  head  come  pugnacity  and  the  various  self- 
assertive  instincts;  here,  too,  fall  the  instincts  for 
collecting  and  secreting  valuables.  These  are  evidenced 
by  the  small  boy's  pocket  and  in  the  tendency  of  the 
miser  to  accumulate  without  reference  to  use.  Closely 
related  to  this  is  the  instinct  of  emulation  or  rivalry. 
This  is  probably  a  mild  form  of  the  fighting  instinct, 
and  may  be  regarded  as  the  basis  of  the  collecting  in- 
stinct so  far  as  that  has  a  social  reference.  Piling  up  a 
vast  fortune  may  be  an  expression  of  the  collecting 
mania  on  the  one  hand,  but  it  also  has  in  it  a  large  meas- 
ure of  rivalry.  To  these  may  be  added  the  hunting 
instinct  with  its  attendant  cruelty,  then  love  of  cruelty 
itself,  which  finds  its  expression  primarily  in  those 
slightly  disturbed  mentally.  To  these  James  would 
add  curiosity,  which  may  be  transformed  into  a  desire 


276        THE  ESSENTIALS  OF  PSYCHOLOGY 

for  information  and  made  a  strong  stimulus  to  educa- 
tion, constructiveness,  and  even  cleanliness,  in  the  form 
of  an  abhorrence  of  filth.  As  in  the  first  group,  it  is 
difficult  to  decide  how  many  of  the  tendencies  grouped 
under  these  various  heads  are  really  instincts,  and  how 
much  they  have  developed  as  habits  or  have  been  trans- 
formed in  part  by  habits  and  experiences  of  various 
sorts.  Probably  something  of  each  is  instinctive,  but 
it  is  always  given  direction  by  habit  and  social  influences. 
The  Racial  Instincts.  —  The  racial  instincts  are  also 
very  numerous  and  are  highly  coloured  by  emotion. 
In  the  lower  animals  they  are  very  widespread  and  very 
striking  for  their  definiteness  and  adequateness,  in  spite 
of  the  slight  knowledge  of  their  purpose  that  can  attach 
to  them.  The  egg-laying  instincts  have  already  been 
illustrated.  The  nest-building  instincts  are  almost  as 
numerous  and  require  greater  complexity  of  response. 
Race  instincts  in  man  are  equally  important  and  have 
as  little  of  their  real  purpose  revealed  in  the  conscious- 
ness of  the  individual  as  corresponding  instincts  of  the 
lower  animals.  The  innocent  adolescent  youth  is 
as  surprised  at  his  thrills  as  he  gazes  upon  the  beautiful 
object  of  his  first  love  and  may  be  as  ignorant  of  their 
cause  and  purpose  as  is  the  beetle  that  is  laying  its  eggs, 
or  the  robin  that  is  building  its  first  nest.  Even  when 
the  instinct  is  understood,  there  is  little  reference  to  that 
knowledge  at  the  moment  and  the  emotion  is  not 
controlled  by  it  and  not  altogether  appreciated  in  its  full 
bearing.  Similar  instincts  without  consciousness  of  pur- 
pose and  in  advance  of  practice  may  be  seen  in  the 
coquetry  of  the  young  girl.  It  apparently  makes  its 


CLASSIFICATION   OF   INSTINCTS  277 

appearance  as  naturally  as  the  unfolding  of  a  leaf, 
although  the  art  may  be  perfect  when  measured  by  the 
most  mature  standards.  To  these  various  love  instincts 
must  be  added  jealousy,  which  may  be  as  spontaneous 
and  unreasoned  as  any  of  the  others.  More  lasting 
are  the  parental  and  filial  instincts  and  the  brotherly 
and  sisterly  affection.  These  are  important  elements  in 
holding  the  family  together.  They  insure  the  care  of 
the  infant  during  the  helpless  stage,  and  the  protection 
and  care  of  the  parent  during  old  age. 

Social  Instincts.  —  The  social  instincts  have  even  a 
wider  range.  They  vary  from  fear  of  a  single  individual 
actually  present,  to  fear  or  consideration  for  the  mass 
of  men  of  the  same  nation  or  race,  even  including  those 
known  only  by  reputation  and  tradition.  The  most 
obvious  expressions  are  seen  in  the  bashfulness  of  a  child 
or  youth  in  the  presence  of  strangers.  Several  recur- 
rent eras  of  bashfulness  may  be  distinguished.  Appar- 
ently the  young  child  ordinarily  goes  through  two  or 
three  stages  in  fairly  close  succession.  It  has  a  period 
of  being  distressed  by  any  stranger,  then  becomes  indif- 
ferent or  pleased  by  people,  then  suffers  another  attack 
of  bashfulness.  Usually  there  is  a  later  increased  sus- 
ceptibility to  bashfulness  about  the  period  of  adoles- 
cence. Stage  fright  and  the  fear  of  man  in  the  mass 
under  unusual  conditions  persist  through  life  and 
apparently  are  overcome  only  by  much  practice,  and 
then  only  for  the  one  situation  in  which  adaptation  has 
developed.  The  opposite  instinct,  sociability,  is  almost 
as  striking  and  shows  itself  during  the  whole  life  of  the 
individual.  From  a  very  early  age,  the  child  resents 


278  THE  ESSENTIALS   OF  PSYCHOLOGY 

being  left  alone,  and  the  desire  for  the  companionship  of 
friends  is  always  very  strong.  When  long  deprived  ot 
the  society  of  his  kind,  one  develops  an  actual  hunger 
for  social  contact  and  conversation. 

The  wider,  more  pervasive  social  instinct  of  sympathy 
is  equally  manifest.  One  cannot  see  the  suffering  of 
another  without  in  some  measure  suffering  oneself. 
When  one  gives  a  coin  to  the  beggar  on  the  street  corner 
one  does  it  not  so  much  to  relieve  the  beggar's  suffering 
as  one's  own.  If  under  the  influence  of  the  teachings  of 
sociology  one  refuses  to  give,  the  thought  of  the  refusal 
will  produce  for  some  time  an  unpleasant  emotion. 
The  instinct  asserts  itself  in  spite  of  the  belief  that  the 
man  is  an  impostor  and  may  be  better  off  than  one's 
self.  Much  has  been  made  of  this  instinct  by  certain 
of  the  modern  schools  of  ethics  as  the  source  of  all  altru- 
istic action,  and  no  doubt  it  deserves  a  very  high  place 
among  the  forces  that  make  community  life  possible. 
Closely  related  to  sympathy,  if  not  merely  other  expres- 
sions of  the  same  instinct,  are  the  instincts  that  lead  to 
self-sacrifice  for  the  larger  group.  The  soldier  when 
he  enlists  exhibits  these  together  with  the  fighting  and 
hunting  instincts.  Every  instance  of  self-sacrifice  is  the 
expression  of  one  or  the  other  of  the  social  or  racial 
instincts.  If  one  asks  how  an  instinct  that  leads  to  the 
possible  destruction  of  the  individual  could  have  survived 
in  the  struggle  for  existence,  one  must  find  the  answer 
in  the  survival  of  the  group  rather  than  of  the  individual. 
Gregarious  animals  are  on  the  whole  more  likely  to  live 
if  the  stronger  are  ready  to  fight  for  the  preservation  of 
the  weaker.  The  male  deer,  that  are  said  to  form  a  circle 


CLASSIFICATION   OF   INSTINCTS  279 

about  the  females  and  the  young  when  attacked  by 
wolves,  make  possible  the  continuance  of  the  species 
even  if  a  large  proportion  of  them  succumb  to  the  attack. 
And  in  the  early  stages  of  human  development  those 
tribes  would  survive  in  which  each  member  would  be 
willing  to  lay  down  his  life  for  the  welfare  of  the  whole. 
Gregarious  animals  survive  in  the  group,  not  individually. 
Complexes  of  Instinct  —  Play.  —  Two  other  instincts 
have  sometimes  been  ascribed  to  man,  —  play  and 
imitation.  It  is  probable,  however,  that  these  are  not 
true  instincts  or  at  least  are  not  single  instincts.  If 
one  will  watch  the  games  of  the  boys  or  girls  upon  the 
school  playground,  one  will  observe  that  each  game  is 
the  expression  of  an  instinct  or  of  many  instincts.  Emu- 
lation or  rivalry  enters  as  a  factor  in  almost  every  con- 
test. Sociability  and  the  advancement  of  the  welfare 
of  the  band  arbitrarily  formed  can  be  traced  in  many 
of  the  sports.  One  may  even  see  evidence  of  instinct 
in  the  content  of  some  of  the  games.  Playing  with 
dolls  is  undoubtedly  an  early  development  of  the  parental 
instinct.  In  general  the  favourite  games  of  each  sex 
show  evidence  of  instinct.  But  the  games  in  their 
specific  forms  are  also  influenced  even  more  by  the 
environment  and  by  the  activities  of  parents  and  friends. 
The  only  thing  that  can  be  said  to  be  common  to  all 
forms  of  play  is  the  tendency  to  some  sort  of  purposive 
activity,  the  inclination  of  the  child  to  be  always  in 
action.  This  is  not  so  much  an  instinct  in  the  ordinary 
sense  as  a  physiological  law,  that  surplus  energy  will 
find  expression  in  action.  Various  instincts  and  habits 
guide  this  expression.  Play  is  the  expression  of  a  law 


280        THE  ESSENTIALS  OF  PSYCHOLOGY 

of  the  physical  organism,  and  so  far  as  it  is  instinctive, 
it  is  the  expression  of  a  number  of  instincts,  not  of  a 
single  one. 

Imitation.  —  Imitation  must  fall  into  the  same  general 
class.  If  we  look  upon  instinct  as  an  inherited  connec- 
tion between  sensory  and  motor  neurones,  it  will  follow 
that  an  instinct  can  be  nothing  more  than  a  tendency  to 
make  a  single  response  or  a  group  of  responses  upon  the 
presentation  of  a  single  stimulus.  Imitation,  on  the 
contrary,  must  always  involve  a  very  large  number  of 
responses  to  many  stimuli.  Imitation  in  general  can  be 
either  the  result  of  many  instincts  or  something  other 
than  instinct.  As  a  matter  of  fact,  it  is  now  one,  now 
the  other.  Some  imitative  acts  are  instinctive,  others 
are  the  result  of  habit  and  learning.  Even  where  learn- 
ing is  involved,  there  is  an  instinctive  element  in  the 
interest  that  one  has  in  the  doings  of  other  people. 
This  general  social  instinct  causes  one  to  observe  the 
movements  and,  where  the  results  are  desirable,  to  make 
an  attempt  to  learn  them.  In  infancy,  the  observa- 
tion of  any  movement  in  another  makes  the  same  move- 
ment interesting  when  it  is  made  by  the  child  himself 
in  the  course  of  chance  responses.  Whatever  the  expla- 
nation, imitation  in  man  leads  to  more  rapid  learning, 
even  where  it  is  not  an  instinct  proper.  Both  play  and 
imitation  have  an  instinctive  basis,  but  neither  is  an  in- 
stinct in  the  same  sense  as  are  eating  and  fear. 

Habit  and  Instinct.  —  It  should  be  added  and  empha- 
sised that  instinct  and  habit  can  seldom  be  altogether 
distinguished.  In  man  at  least,  instinct  is  always  rela- 
tively unstable  and  vague.  An  act  at  its  first  perform- 


HABIT  AND   INSTINCT  28 1 

ance  purely  instinctive  is  soon  modified  by  learning, 
and  a  response  better  suited  to  the  conditions  is  pretty 
certain  to  develop  sooner  or  later,  and  then  to  become 
fixed  in  habit.  This  may  be  seen  in  the  nest-building 
instincts  of  barn  swallows  that  must  at  some  period 
have  built  their  nests  in  natural  objects.  It  can  be 
seen  in  the  control  of  fears  in  man  and  in  most  of  the 
other  instinctive  acts.  In  very  many  instances,  too, 
what  is  instinctive  is  not  the  act  so  much  as  the  attitude 
toward  its  result.  One  dislikes  suffering  and  will  take 
any  known  means  to  get  rid  of  it  or  to  avoid  seeing  it ; 
the  feeling,  not  the  act,  is  instinctive.  The  end  of  re- 
moving the  unpleasant  or  of  obtaining  the  pleasant  may 
be  attained  in  a  number  of  different  ways,  and  the  par- 
ticular means  to  be  used  in  attaining  the  end  is  deter- 
mined by  habit  or  by  intelligence.  Instincts  of  this 
latter  sort  are  not  stereotyped,  as  are  the  earlier,  more 
primitive  acts  of  instinctive  origin. 

Not  only  are  instinct  and  habit  difficult  to  distinguish 
in  practice,  but  habit  is  constantly  repressing  and  chang- 
ing the  instinctive  tendencies.  Instincts  that  have  de- 
veloped in  one  environment  are  not  suited  to  another  and, 
as  was  seen  in  the  nesting  instinct  above,  may  be  replaced 
by  habits  more  appropriate  to  the  surroundings.  More 
often  in  man  the  instinct  comes  into  conflict  with  tradi- 
tion or  convention  that  again  has  probably  developed 
because  better  fitted  than  the  raw  instinct  to  advance 
the  welfare  of  the  social  group.  It  is  bad  form  to  show 
greed,  it  is  not  polite  to  exalt  one's  self.  The  man 
of  good  breeding  restricts  these  impulses  to  the  limits 
set  by  his  fellows.  The  racial  instincts  are  controlled 


282  THE   ESSENTIALS   OF  PSYCHOLOGY 

by  the  laws  of  marriage  and  divorce,  the  individual 
instincts  are  limited  by  customs  and  statutory  enact- 
ments. Both  of  these  checks  probably  take  their  force 
from  the  social  instincts.  The  fact  that  man  seeks 
social  approval,  and  fears  or  avoids  social  blame  is 
probably  largely  due  to  his  instincts.  Certainly,  to 
command  respect  social  disapprobation  need  never 
have  expressed  itself  in  physical  violence  or  the  infliction 
of  bodily  pain.  The  need  for  group  solidarity  has 
become  embodied  in  an  instinctive  respect  for  the 
opinion  of  our  fellows  that  is  at  the  basis  of  what  we 
called  social  pressure  in  the  discussion  of  attention,  and 
is  the  effective  force  behind  both  statutory  enactment 
and  convention.  The  social  forces  that  curb  and  equalise 
the  individualistic  and  racial  instincts  are  themselves  in- 
stincts or  have  a  basis  in  instinct.  It  is  a  social  instinct 
that  receives  its  content  from  tradition  and  custom. 
One  instinctively  respects  custom  or  convention,  al- 
though it  may  have  grown  up  through  habit  and 
tradition. 

Instinct  and  Reflex.  —  If  instinct  is  closely  related 
to  habit  and  cannot  always  be  distinguished  from  it, 
it  is  also  closely  related  to  reflex.  In  fact,  the  definition 
given  of  instinct  as  an  act  dependent  upon  an  inherited 
nervous  connection  will  also  apply  without  change  to 
reflex.  The  infant  draws  back  the  hand  when  burned 
because  of  an  innate  connection  between  the  sensory 
neurone  that  receives  the  stimulus  and  the  group  of 
muscles  that  contract  in  response  to  it.  The  two  terms 
are  confused  in  popular  speech.  As  a  matter  of  fact  in 
psychological  usage  there  is  much  uncertainty  about 


INSTINCT  AND   REFLEX  283 

the  exact  line  that  separates  them.  In  general  one 
speaks  of  a  single  response  as  a  reflex,  of  a  complicated 
series  of  responses  as  an  instinct.  Winking  is  a  reflex, 
the  complex  series  of  acts  involved  in  nest-building  is 
an  instinct.  The  swallowing  movement  aroused  when 
food  touches  the  back  of  the  throat  is  a  reflex,  the  whole 
group  of  processes  involved  in  nursing  is  an  instinct. 
Again  reflexes  often  can  be  easily  reduced  to  a  series 
of  mechanically  determined  responses  to  a  stimulus 
or  series  of  stimuli,  while  the  stimuli  for  instincts  and 
their  relation  to  the  responses  may  not  be  easily  dis- 
covered. One  can  understand  why  one  starts  if  one 
steps  upon  a  tack,  but  it  is  not  so  evident  why  one 
starts  at  a  motion  in  the  grass  that  later  consideration 
shows  might  have  been  a  snake.  One  does  not  know 
at  all  what  stimuli  lead  a  bird  to  fly  south  in  the  fall 
but  one  can  see  a  purpose  in  the  action ;  it  is  an  instinct, 
not  a  reflex.  Finally  there  is  ordinarily  more  con- 
sciousness attaching  to  the  instinct  than  to  the  reflex. 
One  does  not  know  why  one  gives  money  to  the  beggar, 
but  one  is  conscious  of  doing  so,  and  would  feel  uncom- 
fortable were  it  not  done,  but  the  eye  winks  several  times 
a  minute  with  no  appreciation  of  the  dryness  that  stim- 
ulates the  movement  or  of  the  movement  itself.  In 
some  reflexes  the  act  and  the  stimulus  are  conscious  after 
the  act,  but  the  act  itself  is  not  preceded  or  guided  by 
consciousness.  In  most  instincts  all  is  conscious  but 
the  reason  for  the  act.  Instinct  and  reflex  are  to  be 
distinguished  in  terms  of  the  simplicity  of  the  reflex  and 
the  complexity  of  instinct ;  by  the  fact  that  the  reflex  can 
be  understood  from  the  mechanical  activity  of  the  ner- 


284        THE  ESSENTIALS  OF  PSYCHOLOGY 

vous  structures,  while  the  instinct  can  be  referred  to  its 
purpose  alone ;  and  in  terms  of  the  amount  of  conscious- 
ness that  attaches  to  the  instinct.  No  one  of  these 
three  criteria  would  hold  accurately  in  every  case,  but 
taken  together  they  give  an  idea  of  the  nature  of  the  two 
processes. 

Instincts  as  Connate  and  Delayed.  —  It  should  be 
added  in  connection  with  the  differentiation  of  instinct 
from  reflex  and  from  habit  that  the  distinction  cannot 
be  made  on  the  basis  of  the  time  at  which  the  process  or 
activity  makes  its  appearance.  Reflexes  may  be  dis- 
tinguished from  habits  by  the  time  of  their  appearance. 
Reflexes  are  present  at  birth,  are  connate,  while  habits 
require  experience  for  their  development.  Instincts,  on 
the  other  hand,  may  be  either  connate  or  delayed.  They 
may  be  present  at  birth  or  may  appear  only  when  the 
nervous  system  has  attained  a  certain  stage  of  develop- 
ment. It  must  be  said  that  more  of  them  fall  in  the  latter 
group  than  in  the  former.  One  may  recognise  at  birth  the 
rudiments  of  the  food-taking  instincts,  the  vocal  protests 
of  discomfort,  but  relatively  few  others.  The  great  mass 
of  the  individualistic  instincts  and  all  of  the  racial  and 
social  group  are  noticed  only  after  the  nervous  system  has 
ripened,  and  as  has  been  seen,  one  instinct  after  another 
will  show  itself  as  the  organism  develops.  The  appear- 
ance of  one  fear  after  another  in  the  infant  is  to  be  ex- 
plained by  the  fact  that  part  after  part  or  function  after 
function  of  the  cortex  is  developing,  and  at  each  stage 
the  corresponding  stimulus  calls  out  the  reaction  of  fear. 
But  while  instincts  may  not  be  connate,  unlike  habits 
they  are  assumed  to  be  innate.  The  nervous  system  at 


INSTINCT  285 

birth  contains  the  germ  from  which  they  are  developed, 
and  while  they  make  their  appearance  after  some  ex- 
perience has  been  acquired,  it  is  not  because  of  the  ex- 
perience. Classified  with  reference  to  purpose,  instincts 
are  individual,  racial,  and  social ;  classified  with  reference 
to  the  time  of  their  appearance,  instincts  are  connate  and 
delayed. 

Summary.  —  Instincts  are  movements,  or  feelings 
which  may  or  may  not  be  the  result  of  movements, 
that  come  because  of  inherited  connections  and  dis- 
positions in  the  nervous  system.  In  function,  on  the 
one  hand,  they  serve  to  keep  the  infant  alive  until  he 
may  be  able  to  learn  for  himself,  on  the  other,  they 
enforce  general  lines  of  conduct  essential  to  the  pres- 
ervation of  the  individual,  the  race,  and  the  social 
group.  As  opposed  to  habits  and  rational  activities, 
instincts,  of  the  latter  class  at  least,  are  vague  and 
prescribe  only  the  end  to  be  attained,  not  the  precise 
means.  Even  the  first  group  of  instincts  to  make  its 
appearance  is  soon  modified  by  habit,  or  is  repressed. 
Instincts  cannot  be  set  apart  from  habits  and  other  in- 
telligent movements  in  the  adult ;  all  that  can  be  said  is 
that  certain  acts  are  more  largely  instinctive,  others 
more  largely  acquired  on  an  instinctive  basis.  The  ad- 
vantages of  an  inheritance  of  the  vague  outlines  of  action 
only  with  much  left  to  individual  learning  are  evident,  ii 
one  will  but  consider  the  relatively  small  number  of  move- 
ments that  may  be  inherited  and  the  great  number  of 
situations  to  be  met,  not  to  mention  the  great  possibility 
of  change  in  the  environment.  Were  an  organism  to  be 
rigidly  limited  to  a  few  forms  of  response  to  predeter- 


286        THE  ESSENTIALS  OF  PSYCHOLOGY 

mined  conditions,  it  would  soon  find  a  situation  for  which 
it  was  not  prepared  and  be  eliminated.  Or  if  the  en- 
vironment should  change  in  some  way,  the  organism 
could  not  long  survive.  An  endowment  of  few  and 
relatively  indefinite  innate  responses  with  much  capacity 
for  learning  at  once  relieves  the  necessity  for  multi- 
tudinous predetermined  responses  and  assures  the 
preservation  of  the  organism  until  it  has  time  to  learn. 

QUESTIONS 

1.  Which  of  the  following  acts  are  instinctive,  which  reflex: 
Sneezing;    jumping  when  lightly  touched  on  the  shoulder;    the 
nursing  of  a  child ;  nest-building ;  drawing  back  from  the  edge  of  a 
precipice  ? 

2.  What  is  the  neurological  basis  of  instinct? 

3.  Enumerate  five  instincts  that  you  have  exhibited  during  the 
day. 

4.  What  were  the  conscious  accompaniments  of  each  of  the 
above  acts? 

5.  In  what  sense  is  play  instinctive?    imitation?    Do  they 
presuppose  one  or  many  instincts  ? 

6.  Give  instances  in  your  own  responses  of  elimination  of 
instinct  by  social  training. 

7.  Illustrate  from  your  own  experience  a  conflict  between 
individual  and  social  instincts.     Which  won? 

8.  A  dog  has  been  taught  to  beg  for  food.     One  of  her  pups  goes 
through  the  begging  movement  without  having  had  any  opportu- 
nity to  see  its  mother  make  the  movement.     Is  this  an  instinct  ? 
Could  it  have  been  developed  by  training  the  mother? 

9.  If  instincts  do  not  develop  through  habit  how  do  they  arise  ? 

10.  Why  do  individuals  differ  in  the  instinctive  response  to  a 
given  situation? 

11.  Give  an  instance  of  an  instinct  that  has  been  modified  as  a 
result  of  learning,  but  is  still  retained  as  an  instinct  in  the  broad 
outlines. 


CLASSIFICATION    OF   INSTINCTS  287 

REFERENCES 

JAMES  :  Principles  of  Psychology,  vol.  ii,  ch.  xxiv. 
LLOYD  MORGAN  :  Habit  and  Instinct. 

Animal  Behaviour,  chs.  iii,  vii. 
WATSON  :  Behaviour,  ch.  iv. 


CHAPTER  XI 
FEELING 

Feeling  as   Equivalent  to   Selection.  —  One  of   the 

most  striking  and  practically  most  important  features 
in  the  behaviour  of  men  and  of  animals  is  the  preference 
for  certain  objects  or  stimuli.  All  animals  from  the 
protozoa  up  show  a  tendency  to  avoid  certain  objects 
and  to  seek  or  to  remain  near  certain  others.  The 
amoeba  withdraws  its  processes  when  stimulated  by 
some  substances  and  extends  them  towards  and  actually 
enfolds  others.  In  the  higher  animals  a  response  which 
gives  one  result  will  be  repeated  until  the  act  becomes 
habitual,  while  others  will  be  made  but  once.  Move- 
ments of  the  second  class  are  accompanied  by  excess 
movements,  usually  movements  of  withdrawal  which 
may  or  not  be  useful  in  the  particular  environment. 
Such  are  the  shrinking  of  the  dog  at  sight  of  the  whip 
and  the  wry  face  of  the  child  when  the  medicine  bottle  is 
brought  out.  These  are  typical  of  the  process  of  rejection 
as  others  are  of  the  process  of  acceptance.  Common 
observation  indicates  that  most  stimuli  and  most  situa- 
tions fall  into  two  classes :  those  which  evoke  movements 
of  approach  or  cessation  of  movement,  and  those  which 
induce  movements  of  withdrawal.  This  selection  is  prob- 
ably the  most  important  single  factor  in  determining 
the  animals'  habits  and  man's  entire  experience. 
288 


FEELING  AS   BEHAVIOUR  289 

Like  all  of  the  other  facts  of  behaviour,  this  selection 
or  seeming  preference  may  be  approached  from  two 
sides.  From  the  outside  it  has  been  described  above 
in  terms  of  approach  or  quiescence  if  in  contact  with 
the  object  or  of  violent  excess  movements  and  of  lack 
of  movement.  On  the  conscious  side  the  one  is  accom- 
panied by  pleasure,  the  other  by  displeasure.  As  a 
conscious  process  the  difference  between  pleasure  and 
displeasure  seems  to  parallel  many  of  the  most  impor- 
tant distinctions  in  our  lives.  The  movements  that 
are  learned,  objects  that  are  sought,  ideals  that  are 
accepted,  all  are  pleasant,  —  whether  the  pleasure  be 
cause  or  accompaniment  we  need  not  at  present  consider. 
If  we  treat  pleasure  and  its  opposite  as  causes  or  concomi- 
tants of  causes  they  would  be,  like  attention,  important 
agents  in  determining  the  course  of  consciousness  and 
of  action.  Unlike  attention  feeling  is  effective  in  decid- 
ing between  actions  and  the  results  of  action  rather 
than  in  selecting  stimuli.  If  an  act  has  a  pleasant 
result  it  is  repeated,  or  if  one  expects  a  pleasant  result 
from  it  the  act  is  performed.  The  control  of  thoughts 
and  of  sensations  is  not  so  direct  and  complete.  One 
may  seek  pleasant  ideas  but  is  not  always  able  to 
exclude  the  unpleasant,  and  both  pleasant  and  un- 
pleasant stimuli  affect  consciousness  more  readily  than 
indifferent  ones  of  the  same  intensity.  Obviously, 
pleasantness  and  unpleasantness  require  careful  treat- 
ment. Before  we  attempt  to  investigate  their  influ- 
ence upon  behaviour  we  will  describe  them  as  con- 
scious processes  and  assign  them  their  places  among 
other  mental  states. 


200  THE   ESSENTIALS   OF   PSYCHOLOGY 

Uses  of  the  Term.  —  The  term  feeling  is  used  in 
many  different  senses.  It  is  made  to  cover  all  sorts  of 
mental  states,  from  tactual  sensations  to  the  vague 
intellectual  appreciations  of  truth.  We  '  feel '  with 
our  fingers,  and  we  '  feel '  that  certain  things  are  true 
when  we  are  unable  to  prove  them  by  any  formal 
methods.  Feeling  indicates  at  different  times  and  for 
different  people  all  the  vague  experiences.  The  sensa- 
tions from  the  skin  are  regarded  as  less  definite  and 
precise  than  those  from  sight  and  hearing.  In  the  other 
fields  the  same  use  is  predominant.  The  organic  sensa- 
tions are  popularly  classed  as  feelings,  as  are  the  psycho- 
logical processes,  like  recognition  and  belief,  which 
have  not  been  definitely  analysed. 

Obviously  it  is  not  possible  to  discuss  all  of  these  dif- 
ferent states  in  one  chapter  or  in  one  connection.  As 
used,  feeling  stands_for_the  unclassified^ in_eyery_JkkL. 
Wherever  we  have  been  able  to  group  facts  about  certain 
typical  phenomena,  there  are  other  similar  facts  that 
seem  to  belong  in  the  same  group,  but  which  cannot  be 
definitely  ascribed  to  that  class.  These  constitute  the 
feelings  in  the  broader  sense.  Because  they  have  not  yet 
been  reduced  to  types  or  forms,  they  cannot  be  described 
or  defined.  They  are  the  limiting  terms  of  our  science. 
Whenever  they^cease_ to  be  inde_scribable__apd  tfl.ke_nn_ 
definite  form,  they  cease  to  be  feelings.  Evidently, 
feeling  in  this  broader  sense  is  something  that  cannot 
be  discussed ;  when  it  is  possible  to  discuss  it,  it  is  no 
longer  feeling.  Another  objection  to  treating  feeling 
in  this  sense  is  that  there  would  be,  on  this  definition,  as 
many  different  sorts  of  feeling  as  there  are  different 


FORMS   OF   FEELING  291 

classes  of  experience.  The  feeling  of  belief  is  no  more 
like  the  feeling  of  discomfort  from  bodily  illness  than  the 
sensation  of  contraction  is  like  a  syllogism ;  the  feeling  of 
recognition  no  more  like  a  feeling  of  moral  virtue  than  a 
memory  image  is  like  a  voluntary  act.  If  one  were  to 
attempt  'a  discussion  of  feelings  in  this  sense,  a  separate 
treatment  of  each  would  be  necessary,  and  it  would  be 
most  convenient  to  discuss  them  in  connection  with  the 
experiences  of  the  same  group  that  already  have  been 
analysed  and  reduced  to  laws. 

Feeling  as  Pleasantness  and  Unpleasantness.  — 
Pleasantness  and  unpleasantness  are  the  only  definite 
mental  states  to  which  the  term  feeling  is  applied.  A 
description  of  them  is  as  difficult  as  of  any  simple  process, 
but  there  is  no  doubt  what  is  meant  when  the  word  pleas- 
antness or  unpleasantness  is  used.  Pleasantness  and  un- 
pleasantness are  general  and  are  found  in  connection 
with  practically  every  other  state.  They  may  be 
induced  by  impressions  from  any  sense,  and  by  mem- 
ories of  many  different  qualities.  They  are  found 
as  the  accompaniments  of  different  actions,  in  fact 
are  attached  to  all  sorts  and  conditions  of  mental  pro- 
cesses. Pleasantness  and  unpleasantness  are  really 
distinct  mental  qualities  and  deserve  a  special  name, 
whatever  it  may  be.  Psychologists  are  agreed  in  call- 
ing these  two  qualities  feelings,  no  matter  what  other 
qualities  they  may  add  to  the  list.  We  can  decide  arbi- 
trarily to  regard  pleasantness  and  unpleasantness  as  the 
feeling  qualities  and  omit  the  others,  not  because  they 
are  unimportant  in  themselves,  but  because  they  are  not 
feelings  on  the  same  level.  So  far  as  a  discussion  of 


2Q2        THE  ESSENTIALS  OF  PSYCHOLOGY 

them  is  possible,  it  is  carried  on  to  better  advantage 
in  connection  with  other  subjects. 

Differences  between  Feeling  and  Sensation.  —  Even 
if  we  grant  that  pleasantness  and  unpleasantness  are 
peculiar  states  of  consciousness,  the  question  is  raised 
whether  they  are  distinct  from  sensations.  Ordinarily^ 
feelings  arise  through  excitation  by  some  stimulus  and 
are  closely  connected  in  origin  with  sensations.  But  we 
may  have  both  feelings  and  sensations  from  the  same 
stimulus  at  the  same  time  and  can  always  distinguish^, 
them.  The  two  are  never  confused!  Many  formal 
arguments  have  been  de vised  to  show 'that  they  are 
really  different  sorts  of  mental  content.  Perhaps  the 
most  striking  is  the  general  dependence  of  the  feeling 
upon  the  individual  and  his  peculiar  experiences.  When 
the  same  stimuli  affect  us,  we  see  approximately  the  same 
things,  but  we  feel  very  differently  at  different  times. 
What  pleases  at  one  time  may  displease  at  another. 
What  one  feels  r|p|wwjgjipon  tl^inrhViHiiqLand  hjs  mood_ 
at  the  moment,  as  opposed  to  the  nature  of  the  external 
stimulus  which  determines  the  nature  of  sensation. 
Feeling  is  as  much  subjective  as  attention,  while  sensa- 
tion is  dependent  altogether  upon  the  physicaLemdron^ 
ment.  It  is  in  this  sense  that  feelings  are  subjective, 
sensations  objective.  Coupled  with  this  subjective 
character  is  the  further  fact  that  an  experience  when 
recalled  does  not  always  have  the  same  feeling  as  at 
first.  What  pleased  at  one  time  as  a  boyish  prank 
may  cause  mortification  in  maturer  years.  In  the  same 
way  an  early  social  blunder  that  occasioned  keen  chagrin 
at  the  time  may  now  excite  nothing  but  mild  amusement. 


FEELING   AND    SENSATION    •  293; 

The  individual  has  changed  in  the  meantime  and  the 
feelings  change  with  him.  That  feelings__undergo 
change  between  the  actual  experience  and  the  recalj 
has  led  to  the  statement  that  we  cannot  remember 
them.  It  is  true  that  we  cannot  recall  the  pleasantness 
in  all  of  its  warmth,  but  we  do  recall  the  sensational 
elements  and  receive  the  same  feeling  as  if  they  were  ex- 
perienced at  present.  We  undoubtedly  remember  that 
we  were  pleased  or  displeased,  or  there  would  be  no  ques- 
tion about  the  change  in  feeling.  The  remembrance 
is  in  words  or  other  conceptual  terms. 

This  subjectivity  or  dependence  upon  the  nature  of 
the  individual  and  his  momentary  mood  is  the  most  strik- 
ing characteristic  of  feeling.  Closely  related  to  it  isjls- 
lack  of  anything  that  partakes  of  definiteness  or  of  a 
conceptual  character.  Feelings  seem  to  vanish  when  one 
attempts  to  describe  them  or  even  to  attend  to  them. 
Any  attempt  to  analyse  the  characteristics  of  pleasure 
brings  about  a  diminution  if  not  the  disappearance  of  the 
pleasure.  Even  to  ask  whether  one  is  really  pleased  or 
not  has  much  the  same  effect  in  smaller  degree.  Pleasure 
vanishes  when  examined  carefully.  The  mood  of  analy- 
sis is  not  conducive  to  pleasure  and  in  less  degree  is  not 
conducive  to  displeasure.  These  general  characteristics 
of  the  feelings  seem  sufficient  to  mark  them  as  distinct 
mental  qualities.  Pleasantness  and  unpleasantness  must 
be  regarded  as  belonging  in  a  different  class  from  sensa- 
tions. 

The  Quality  of  Feeling.  —  Feeling  is  much  less  rich  in 
qualities  than  sensation.  The  qualities  upon  which  there 
is  general  agreement  are  pleasure  and  displeasure,  or 


2Q4        THE  ESSENTIALS  OF  PSYCHOLOGY 

pleasantness  and  unpleasantness.  They  are  both  op- 
posed to  indifference.  Indifference  by  some  authors  has 
been  made  a  distinct  class  in  addition  to  pleasure  and 
displeasure.  Indifference,  however,  is  probably  merely 
the  lack  of  feeling  and  is  applied  only  to  the  stimulus 
or  to  sensation.  An  indifferent  stimulus  is  one  that 
does  not  give  rise  to  feeling ;  there  are  no  indifferent 
feelings.  There  are  but  two  qualities  of  feeling,  although 
stimuli  that  arouse  feelings  may  be  opposed  to  indifferent 
stimuli  or  sensations.  The  intermediate  position  is  more 
suggestive  if  we  consider  the  degrees  of  pleasantness  and 
unpleasantness  and  their  relation  to  the  intensity  of  the 
stimulus.  Pleasure  and  its  opposite  vary  in  degrees  in 
both  directions  from  just  appreciable  to  very  intense 
feelings.  Wundt  early  suggested  that  there  was  a  con- 
stant relation  between  the  intensity  of  the  stimulus  and 
the  nature  and  degree  of  the  feeling.  Faint  stimuli  are 
ordinarily  pleasant  and  become  less  and  less  pleasant  as 
they  increase  in  intensity,  becoming  first  indifferent  and 
then  unpleasant.  Slightly  sweet  substances  are  indif- 
ferent or  disagreeable.  As  the  degree  of  sweetness  in- 
creases, the  substance  becomes  pleasant,  while  the  intense 
sweet  of  saccharine  is  unpleasant.  This  relation  holds 
approximately  for  some  senses  but  it  cannot  be  re- 
garded as  a  general  law. 

Feeling  and  Affection.  —  It  has  often  been  asserted 
that  there  must  be  different  feelings  for  each  sense 
department,  and  even  for  each  sense  quality.  This 
depends  upon  the  fact  that  one  does  not  distinguish 
between  the  feeling  proper  and  the  accompanying  sen- 
sations. The  sensations  in  the  complexes  are  different 


FORMS   OF   FEELING  2Q5 

and  make  the  whole  complex  different.  The  feeling 
proper  is  not  discriminated  from  the  sensational  colour- 
ing. The  elementary  feeling  process  is  often  confused 
with  the  complex,  even  in  psychological  writing  and 
thinking.  To  avoid  the  confusion  it  has  become  usual 
to  apply  the  term  '  affection  '  to  the  mere  pleasantness 
and  unpleasantness  apart  from  the  sensational  com- 
ponents, and  to  keep  the  word  '  feeling  '  for  the  complex. 
For  example,  in  a  toothache  we  can  distinguish  the 
sensation  pain  from  the  reaction  against  the  pain.  It 
is  this  reaction  that  we  call  the  unpleasant  '  affection.' 
The  disadvantage  of  using  '  affection  '  to  designate  the 
element  is  that  it  has  such  a  widely  accepted  popular 
usage  as  the  name  of  an  emotion.  However,  we  shall 
find  it  convenient  to  use  the  term  in  default  of  a  better 
one.  Accepting  this  usage,  we  may  assert  that  all 
affections  are  of  two  kinds,  pleasant  and  unpleasant, 
and  that  all  differences  in  feelings  are  due  to  the  differ- 
ent concomitant  sensations.  The  difference  between  a 
toothache  and  a  headache  lies  in  the  localisation  of  the 
pain  sensations,  and  perhaps  in  some  of  the  accompany- 
ing organic  sensations. 

Sensation  of  Pain  and  Unpleasantness.  —  Particularly 
close  is  the  relation  between  the  affection,  unpleasant, 
and  the  sensation,  pain,  which  is  nearly  always  unpleas- 
ant. The  affection  andjthe^  sensation  are  combined^sp 
_a^  single  feeling  that  frequently  they  are  not 


^istinguished_at_ajl7  ATTew  years  ago  it  wasusual  to 
confuse  the  two  and  speak  of  feelings  of  pain  as  well  as 
of  feelings  of  unpleasantness.  Since  pain  organs  have 
been  recognised,  this  usage  is  not  to  be  favoured  unless 


296  THE  ESSENTIALS   OF  PSYCHOLOGY 

the  term  pain  is  used  in  two  senses,  —  to  designate  both 
the  affection  and  the  sensation.  Pain  sensations  may 
be  pleasant,  as  in  the  pain  excited  by  the  biting  cold  of 
a  clear  day  when  one  is  in  good  health.  The  displeasure 
caused  by  a  sudden  pain  is  altogether  distinct  from  the 
pain  itself,  although  they  are  fused  into  a  single  complex. 
The  quality  of  unpleasantness  apart  from  its  setting  is 
the  same  in  each  case.  We  may  conclude  that  there  are 
but  two  qualities  of  affection  and  that  differences  in  feel- 
ing come  from  the  sensational  elements  in  the  complex, 
not  from  the  affective  components. 

Sensory  and  Intellectual  Feelings.  —  Other  suggested 
•distinctions  are  between  higher  and  lower,  or  sensory  and 
intellectual  feelings.  In  general  the  two  classes  overlap. 
Intellectual  feelings  on  the  whole  are  supposed  to  be 
higher ;  the  sensory,  lower.  The  difference  between  the 
intellectual  and  the  sensory  is  very  much  the  same  as  that 
between  the  different  sorts  of  sensory  feelings  discussed 
in  the  preceding  paragraph.  In  the  intellectual,  the 
cognitive  components  are  largely  memory  processes  and 
products  of  imagination.  Mental  accomplishments  of 
all  kinds  give  rise  to  pleasure ;  defeat  or  failure  to  per- 
form a  mental  operation  resolved  upon  causes  displeasure. 
The  resulting  pleasure  or  displeasure  is  the  same  in  each 
instance;  the  difference  is  in  the  occasion  alone,  the 
non-affective  accompaniments  of  the  pleasure.  Between 
the  higher  and  lower  pleasures  the  distinction  is  largely 
in  terms  of  ethical  or  social  values,  rather  than  in  the 
quality  of  the  affection.  The  higher  pleasures  are  those 
that  are  important  for  the  welfare  of  society  and  corre- 
spond to  activities  not  deeply  ingrained  by  instinct. 


FEELING  AND   BODILY   STATES  297 

Society  has  given  an  indorsement  to  the  pleasures  of 
the  one  class  because  of  their  benefit  to  the  social  whole, 
while  the  pleasures  of  sense  are  regarded  as  strong  enough 
to  take  care  of  themselves.  The  pleasure  from  a  good 
dinner  is  apparently  no  different  in  its  quality  from  the 
consciousness  of  a  good  deed,  but  the  pleasure  attaching 
to  a  good  dinner  is  sufficiently  vivid  and  the  instinct  to 
eat  sufficiently  strong  to  need  no  bolstering  from  society, 
while  the  instinct  to  perform  a  good  deed  is  so  weak  that 
social  approval  is  necessary  to  insure  its  performance. 
Society  therefore  expresses  its  approval  by  classifying 
the  one  pleasure  as  higher,  while  its  disapproval  of  the 
other  is  expressed  by  classifying  it  as  lower.  Neither 
of  these  classifications  has  reference  to  the  affective 
quality,  and  so  makes  necessary  no  change  in  our  earlier 
statement  that  affections  have  but  two  qualities,  pleas- 
ure and  displeasure. 

Bodily  Accompaniments  of  Feelings.  —  The  bodily 
accompaniments  of  feelings  have  been  made  much  of 
in  psychological  descriptions  and  discussions.  Many 
bodily  signs  of  pleasure  are  apparent  to  the  casual  ob- 
server. When  one  is  pleased,  the  face  is  flushed  due 
to  the  enlarged  capillaries,  the  eye  is  bright  from  the 
dilation  of  the  pupil  and  the  slight  secretion  of  tears, 
the  carriage  is  erect.  In  displeasure  the  opposed  re- 
sponses are  seen.  Attempts  have  been  made  to  deter- 
mine accurately  the  different  component  physiological 
changes  that  give  rise  to  the  psychical  condition,  but  at 
present  the  results  are  conflicting.  No  exact  opposition 
can  be  shown  between  pleasure  and  pain  in  the  accom- 
panying heart  rate,  in  the  size  of  the  capillaries,  or  in 


298         THE  ESSENTIALS  OF  PSYCHOLOGY 

the  strength  or  rate  of  breathing.  All  of  these  processes 
undergo  change  in  any  sort  of  feeling,  but  one  cannot 
connect  the  nature  of  the  change  with  the  quality  of 
feeling.  All  that  can  be  said  is  that  the  changes  are 
more  marked  in  displeasui^..than__in_^leasure.  The 
belief  of  the  earlier  investigators-  that  they  had  discovered 
a  definite  relation  between  the  bodily  responses  and 
pleasure  and  displeasure  does  not  harmonise  with  the 
results  of  recent  investigations. 

Theories  of  Feeling.  —  Three  theories  have  value  as 
an  explanation  of  the  nature  and  origin  of  feeling  or  of 
the  affective  component  of  the  feeling.  These  are: 
(i)  the  evolutionary  theory  which  is  oldest  and  prob- 
ably fundamental  for  the  other  two;  (2)  the  theory 
that  relates  feeling  to  association  and  attention;  and 
(3)  the  theory  of  smooth-running  and  checked  mental 
operations.  Each  has  its  place  and  must  be  considered 
separately.  The  first  asserts  that  pleasure  is  the  ac- 
companiment of  stimuli  that  have  in  the  long  run  proved 
beneficial  to  the  race ;  displeasure,  the  accompaniment 
of  stimuli  that  on  the  whole  have  proved  injurious.  We 
like  foods,  we  dislike  substances  that  are  unfit  for  food. 
There  are  obviously  many  exceptions  to  this  rule,  but 
they  arise  largely  from  the  fact  that  man  has  evolved, 
not  to  meet  each  specific  case,  but  to  meet  the  general 
conditions.  Thus  sugar  of  lead  might  be  mistaken  for 
cane  sugar  and  be  considered  pleasant,  but  to  avoid  all 
sweets  would  be  more  injurious  to  the  race  than  to  eat 
all  and  have  the  few  die  who  chance  upon  the  poisonous 
sweets.  Similarly  medicines  are  proverbially  unpleas- 
ant, but  man  was  not  evolved  to  take  medicine.  They 


THEORIES   OF   FEELING  299 

are  of  value  only  in  exceptional  conditions.  On  this 
theory,  man's  action  has  been  adjusted  to  the  environ- 
ment, and,  as  a  part  of  the  process,  there  has  been  de- 
veloped a  conscious  foreshadowing  of  the  effect  of  certain 
substances  upon  him.  The  promise  of  benefit  from  a 
stimulus  constitutes  its  pleasantness;  the  warning  of 
injury  its  unpleasantness.  The  feelings  come  in  ad- 
vance of  specific  experience.  They  are  of  value  in 
planning  action.  In  many  instances  the  idea  arouses 
pleasure  before  the  action  is  begun,  or  even  before  the 
stimulus  is  received.  If  the  anticipation  of  the  results 
of  an  act  is  pleasant,  it  is  executed,  if  unpleasant  it  is 
inhibited.  Metaphorically,  one  may  regard  the  feelings 
as  organic  memories  of  the  effect  of  stimuli  upon  the 
race  as  a  whole,  come  to  light  in  the  individual  as  a 
member  of  the  race.  As  a  matter  of  actual  fact,  all 
that  this  can  mean  literally  is  that  all  individuals  who 
felt  anything  other  than  pleasure  from  beneficial  stimuli, 
or  other  than .  displeasure  from  injurious  stimuli  and 
ideas  have  been  eliminated.  Evolution  and  elimination 
have  found  expression  in  tendencies  to  action  and  in 
feelings  that  now  signify  for  all  individuals  the  general 
relations  of  the  stimuli  to  the  benefit  or  injury  of  the 
organism. 

The  Experience  Theory  of  Feeling.  —  The  first  of  the 
psychological  theories  of  feeling  seeks  to  explain  the 
changes  that  feelings  undergo  as  the  individual  grows. 
One  of  the  most  striking  phenomena  in  connection  with 
feelings  is  that  they  change  their  character  with  the  ex- 
perience of  the  individual.  An  unfortunate  experience 
with  a  particular  dish  may  make  it  unpleasant  long  after 


300        THE  ESSENTIALS  OF  PSYCHOLOGY 

the  experience  itself  has  passed  out  of  mind.  Some  pleas- 
ures, too,  are  the  direct  expression  of  association.  A 
national  anthem  arouses  a  pleasure  in  the  patriotic 
citizen  entirely  incommensurate  with  the  artistic  value 
of  the  music.  Wundt  carries  the  theory  a  step  farther 
and  relates  feeling  to  the  activities  at  the  basis  of  atten- 
tion. The  accumulated  experiences  largely  determine 
the  character  of  attention.  The  character  of  feeling 
depends  upon  the  experiences  of  the  individual.  These 
two  statements  may  be  combined  in  the  theory  that 
feeling  is  the  outcome  of  attention.  The  ultimate 
quality  of  the  feeling  as  pleasant  or  unpleasant  must 
still  be  explained  by  the  evolutionary  theory.  There 
is  nothing  involved  in  attending  to  a  pleasant  object 
that  is  not  also  involved  in  attending  to  an  unpleasant 
one.  Accumulated  experience  only  serves  to  transfer 
the  pleasure  and  displeasure,  derived  originally  from 
one  experience,  to  others  with  which  they  were  not  at 
first  connected.  The  pleasure  of  a  song  may  at  first 
be  due  to  the  social  instincts  that  have  their  source  in 
the  community  of  spirit  with  fellow-members  of  the 
group.  Later  the  pleasure  returns  when  the  song  is 
heard.  All  goes  back  to  the  appreciation  of  benefit  and 
injury,  but  appreciation  is  rendered  more  certain  and 
accurate  by  the  later  experiences.  The  evolutionary 
quality  or  character  is  extended  from  the  immediately 
pleasant  stimuli  to  other  and  related  stimuli  and  quali- 
ties of  sensation. 

The  Furtherance-Hindrance  Theory.  —  The  third  the- 
ory is  favoured  by  Stout  and  Dewey  in  slightly  dif- 
ferent forms.  It  makes  pleasure  the  accompaniment 


THEORIES   OF   FEELING  301 

of  any  smooth-running,  uninterrupted  activity ;  dis- 
pleasure, of  thwarting  and  interruption.  If  one's  heart 
is  set  upon  the  accomplishment  of  any  task  and  the 
task  is  interrupted  in  its  performance,  displeasure  is 
the  result.  Whatever  furthers  the  progress  of  the  task 
gives  pleasure.  What  the  task  is  matters  not.  It  is  as 
truly  pleasant  to  progress  toward  the  solution  of  a 
problem  in  mathematics  when  that  is  the  aim  of  the 
moment  as  it  is  toward  the  acquisition  of  an  automobile 
or  the  worldly  wealth  v/hich  that  signifies.  There  is 
undoubtedly  a  very  close  relation  between  pleasure  and 
progress  toward  a  desired  end.  The  possibilities  of 
pleasure  are  dependent  largely  upon  desires.  This 
theory  applies  immediately,  however,  only  to  relatively 
active  processes  or  operations.  The  application  is  ex- 
tended by  the  use  of  many  similes.  The  more  general 
asserts  that  there  are  many  more  movements  than  one 
ordinarily  assumes,  that  movements  are  called  out  in 
relatively  obscure  muscles  and  organs  that  one  would 
never  suspect  to  play  any  part  in  the  operation.  Lipps 
has  suggested  that  these  movements  are  evoked  by 
sympathy,  —  that  we  personify  inanimate  objects  and 
then  suffer  or  rejoice  with  them.  A  column  that  seems  to 
be  supporting  a  load  beyond  its  strength  excites  our  sym- 
pathy because  we  put  ourselves  in  its  place.  Many  geo- 
metric figures  excite  our  compassion  and  so  are  unpleasant, 
others  are  pleasant  from  their  complete  adequacy. 

All  Three  Theories  are  Needed.  —  Each  of  these 
theories  has  its  applications.  The  more  fundamental 
activities  and  reactions  must  find  their  explanation  in 
the  evolutionary  feeling.  Fundamentally,  the  organism 


302  THE   ESSENTIALS   OF   PSYCHOLOGY 

requires  satisfaction  in  certain  ways,  and  there  is  appar- 
ently a  predisposition  to  respond  to  certain  stimuli  by 
the  feeling  of  pleasure,  to  others  by  displeasure.  Under 
this  head  come  the  sense  pleasures.  The  associatory 
theory  will  explain  the  many  transfers  and  changes  in 
feelings  in  the  course  of  our  life,  and  the  attachment 
of  feelings  to  many  objects  that  are  themselves  indiffer- 
ent to  our  well-being.  On  the  contrary,  the  opposition- 
furtherance  theory  is  best  adapted  to  the  explanation 
of  the  active  pleasures,  both  physical  and  mental. 
Most  pleasure  from  games  finds  its  explanation  in  ac- 
complishment ;  and  the  pleasure  that  accompanies  suc- 
cess in  any  undertaking  has  the  same  explanation. 
Feelings  cannot  be  explained  by  any  one  theory  as 
there  are  different  sources  of  pleasure  and  displeasure. 
All  three  theories  must  be  combined  if  feelings  are  to 
be  understood  in  their  entirety. 

QUESTIONS 

1.  Distinguish  feeling  from  affection.     What  is  the  popular, 
what  the  psychological  meaning  of  each  word? 

2.  Find  cases  which  prove  or  disprove  the  statements  (a)  that 
sensations  are  objective,  affection,  subjective ;   (6)  that  sensations 
are  clearer  with  attention,  affection  less  prominent ;    (c)  that 
sensations  have  a  definite  sense-organ,  affections  have  not. 

3.  How  can  you  remember  an  affection  ? 

4.  What  are  the  qualities  of  affection?  of  feeling? 

5.  Can  you  give  pleasantness  or  unpleasantness  a  definite  bodily 
seat  as  you  examine  any  simple  experience  ? 

6.  What  is  the  real  distinction  between  higher  and  lower  feel- 
ings?   Is  it  in  the  qualities  of  the  affection? 

7.  Is  the  pleasure  recalled  in  Question  2  instinctive,  the  result 
of  training  or  experience,  or  an  expression  of  furthered  or  successful 


FEELING  303 

activity  ?    Recall  different  pleasures  that  can  be  explained  by  each 
of  the  theories. 

8.  Give  instances  in  which  pleasure  has  not  been  a  satisfactory 
guide  to  conduct.  How  do  you  explain? 

EXERCISES 

1.  Sometime,  when  much  pleased  at  some  happening,  turn 
around  upon  yourself  and  try  to  analyse  the  state  into  its  elements. 
Can  you  distinguish  the '  affective '  elements  in  the  total  state  from 
the  sensational  components  ?    Does  the  pleasure  disappear  during 
the  analysis? 

2.  Try  to  recall  some  pleasure  of  last  week.     Do  you  reinstate 
the  pleasure  or  remember  that  you  were  pleased  ?     In  your  opinion 
is  the  pleasure  as  intense  as  in  the  original  experience?    Do  you 
recall  the  pleasure  in  its  vividness,  or  merely  the  sensations  that 
were  connected  with  the  experience  ? 

3.  Make  a  list  of  twenty  events  in  your  past  that  were  strongly 
pleasant  or  unpleasant  at  the  time.     What  is  your  present  reaction 
to  each  ?    Is  there  any  law  as  to  change  in  tone  ? 

4.  Watch  the  pupil  of  an  assistant  as  you  stimulate  first  with 
pleasant  then  with  unpleasant  odours.     Record  direction  of  change 
in  size. 

Count  the  number  of  breaths  for  a  minute,  first  under  pleasant, 
then  under  unpleasant  odours.  Is  there  a  difference  ?  Record  any 
checking  or  quickening  of  respiration  after  stimulus  is  given. 

5.  Prepare  a  series  of  crosses  with  an  upright  an  inch  long  and 
cross-bars  three-fifths  of  an  inch  long.     Place  the  cross-bar  on  one 
one-tenth  of  an  inch  from  the  top,  the  others  each  a  tenth  of  an 
inch  farther  down.     Ask  ten  or  more  individuals  to  arrange  them 
in  order  of  pleasantness.     Which  is  most  often  preferred?     Can 
you  explain  the  choice  by  any  of  the  theories  of  feeling? 

REFERENCES 

ANGELL  :  Psychology,  chs.  xiii,  xiv. 
TITCHENER:  Text-book  of  Psychology,  pp.  225-264. 
STOUT:  Manual  of  Psychology,  pp.  210—241. 
MARSHALL  :  Pain,  Pleasure,  and  Esthetics. 


CHAPTER  XII 
THE  EMOTIONS 

The  Place  of  Emotion  in  Consciousness.  —  The  emo- 
tions stand  as  mental  states,  intermediate  between  feel- 
ings and  instincts  and  the  higher  intellectual  operations. 
From  one  point  of  view,  they  are  very  intense  and  diffuse 
feelings  aroused  by  complicated  situations.  Pleasure  is 
the  result  of  a  mild  response ;  delight,  of  a  response  of 
the  same  general  character  but  more  intense  and  diffuse. 
Emotions,  too,  are  related  to  movements.  It  was  said 
at  the  beginning  of  the  last  chapter  that  stimuli  which 
were  accepted  frequently  aroused  slight  diffused  move- 
ments or  were  accompanied  by  quiescence,  while  stimuli 
that  were  rejected  nearly  always  induced  vigorous  move- 
ments of  a  different  character.  These  incidental  and 
apparently  useless  movements  not  merely  indicate  to 
the  observer  the  likelihood  of  continued  and  repeated 
acceptance  or  rejection,  but  also  give  a  definite  colour- 
ing to  the  accompanying  consciousness.  When  sur- 
prised, one  starts ;  when  one  thinks  of  some  definite 
action  to  perform,  one  executes  it.  In  this  respect 
emotion  is  different  from  voluntary  action  since  the 
movements  in  an  emotion  have  no  necessary  relation 
to  the  outside  world,  but  find  their  goal  within  the  body. 
Injemotion,  action  ends  with  facial  expression  or  diffuse 
304 


THE   EMOTIONS  305 

organic  responses ;  in  action  of  the  .voluntary  sort,  the 
end  of  movement  is  some  change  in  the  world  outside. 
In  one  sense  emotion,  like  feeling,  is  an  expression~of 
instinct.  All  emotionsjhave  an  instinctiyejrasis ;  move- 
ments in  emotional  expression  are  the  outcome  of  in- 
stinct. So  true  is  this,  that  the  emotion  has  been  denned 
by  Dewey  and  MacDougall  as  the  conscious  side  of 
instinct.  For  instance,  fear  is  instinctive,  but  fear  is 
also  an  emotion.  Jnstinct  is  the  process  viewed  from 
the  outside,  emotion  is  the  same  process  viewedjrojii. 
within.  Every  emotion  has  its  instinctive  side,  every 
instinct  its  emotional  side.  Emotion  is  concerned  pri- 
marily with  the  responses  that  end  altogether  within  the 
body;  impulses  are  the  instincts  that  lead  to  action 
directed  beyond  the  body  and  will  be  discussed  in  the 
next  chapter. 

Ancient  Theories  of  Emotion. —  The  ancients  always 
spoke  of  the  emotions  as  having  their  seat  in  the  viscera. 
Courage  was  in  the  heart,  jealousy  in  the  liver,  and 
several  of  the  other  emotions  had  their  seat  in  the  ab- 
dominal region.  Study  of  an  emotion  whether  during 
immediate  experience  or  when  recalled  shows  that  many 
of  its  components  are  sensations  from  the  various  parts 
of  the  body.  In  sorrow  there  is  pressure  about  the  heart, 
in  joy  a  feeling  of  lightness  in  the  chest.  The  lump  in 
the  throat,  the  dryness  of  the  membranes  of  the  mouth, 
all  contribute  some  part  to  the  total  emotion.  Organic 
sensations  constitute  a  large  part  of  what  can  be  de- 
scribed or  remembered  of  the  emotions.  These  have  a 
definite  bodily  seat  in  the  chest  and  abdomen,  and  seem 
to  be  more  or  less  closely  related  to  the  vital  organs. 


306        THE  ESSENTIALS  OF  PSYCHOLOGY 

This  fact  explains  why  the  ancients  ascribed  the  emotions 
to  these  organs. 

James-Lange  Theory.  —  The  recent  discussions  follow 
the  same  general  tendency.  The  prevailing  modern 
theory  was  developed  independently  by  James  and 
Lange.  This  theory  makes  emotion  the  subjective 
accompaniment  and  the  natural  outcome  of  instinct. 
When  a  stimulus  affects  one,  it  calls  out  numerous  re- 
sponses because  of  the  inherited  paths  of  discharge. 
These  are  the  occasion  both  for  the  bodily  attitudes  as 
they  are  presented  to  the  outside  observer,  and  for  the 
consciousness  of  the  emotion  as  it  is  revealed  to  the 
man  himself.  Professor  James  insists  that  ordinarily 
there  is  no  awareness  of  the  emotion  until  the  action 
has  been  completed.  For  instance,  he  asserts  that  as 
a  small  boy  he  was  playing  with  blood  without  knowing 
what  it  was.  Suddenly  he  fainted.  Nothing  in  the 
experience  suggested  the  act  or  gave  any  indication 
that  he  was  about  to  faint.  He  generalises  this  fact 
in  the  assertion  that  the  consciousness  of  the  emotion 
always  attaches  to  the  act  after  it  has  been  completed. 
"  One  sees  a  bear  and  runs  away.  One  is  afraid  because 
one  runs  away ;  one  does  not  run  away  because  one  is 
afraid."  The  act  comes  instinctively  as  part  of  the 
stimulus ;  no  thought  intervenes,  no  elaborate  working 
over  of  the  material  is  possible  before  the  responses 
which  constitute  the  expression  and  give  rise  to  the 
emotion  as  mental  process. 

Emotion  as  Instinctive  Response.  —  The  theory  of 
emotion  in  terms  of  the  instinctive  response  is  very 
generally  accepted.  There  can  be  no  doubt  that  most 


EMOTION   AND    INSTINCT  307 

of  the  vividness  and  life  of  the  emotion  depends  upon  the 
bodily  expression.  One  is  not  really  afraid  unless  one 
feels  the  general  quaking  and  motor  insufficiency  to- 
gether with  the  sinking  feelings  about  the  heart.  One 
is  not  really  angry  unless  one  is  going  hot  and  cold  and 
has  lost  control  of  the  muscles  to  some  degree.  A  man 
who  could  face  a  crisis  and  know  it  to  be  a  crisis  with 
none  of  these  organic  responses  would  not  really  feel 
an  emotion,  no  matter  how  complete  intellectual  appreci- 
ation he  had  of  the  seriousness  of  the  situation.  The 
emotions  take  their  colour^  from  the  bodily  reverbera- 
tion, from  the  sensations  that  arise  from  contracting^ 
.muscles.  These  contractions  are  aroused  by  the  in- 
stinctive connections  between  the  stimulus  and  the 
muscles.  Up  to  this  point  the  character  of  the  emotions 
is  determined  instinctively.  That  the  emotions  would 
not  have  the  qualities  they  do  have  without  these  in- 
stinctive responses  is  demonstrated  by  the  observations 
of  the  pathologists,  that  when  an  individual  has  wide- 
spread anaesthesia  of  the  body  muscles,  no  emotions  are 
felt  or  at  best  the  emotions  are  not  of  the  same  character 
as  in  the  normal  individual.  vThe  deep-seated  motorjre- 
sponsc  is  an  integral  part  of  the  emotion ;  the  emotion 
disappears  or  takes  on  an  entirely  different  character 
when  the  response  is  lacking. 

Evidence  for  the  James  Theory.  —  Sometimes  the 
objection  is  raised  that  one  does  not  feel  the  emotion 
when  it  is  merely  feigned,  although  this  may  include 
making  most  of  the  movements  involved  in  the  or- 
dinary emotional  expressions.  This  suggestion  led 
James  to  ask  actors  whether  they  felt  the  emotions;- 


308        THE  ESSENTIALS  OF  PSYCHOLOGY 

they  depicted.  As  might  have  been  expected,  actors 
divided  into  classes.  Some  felt  the  emotions  they 
portrayed,  others  were  left  practically  unmoved.  More- 
over, one  could  not  say  that  there  was  any  relation 
between  the  strength  and  accuracy  of  the  acting,  and 
the  degree  to  which  the  part  was  felt.  Great  actors 
were  left  cold  and  equally  great  ones  felt  the  emotion. 
The  difference  arises  probably  from  the  fact  that  some 
individuals  must  feel  the  part  to  express  it,  others  are 
able  to  mould  the  features  without  having  the  complete 
bodily  reaction  aroused.  It  is  probable,  too,  that  in 
many  cases  an  actor  can  separate  the  more  superficial 
from  the  deeper  responses;  he  can  control  the  muscles 
of  the  face  and  the  larger  muscles  of  the  trunk  without 
making  the  associated  contractions  of  the  deeper-lying 
muscles.  The  amount  of  feeling  depends  upon  the  num- 
ber of  such  deeper-lying  muscles  that  are  contracted. 

Specific  Physiological  Responses  in  Emotion.  —  Im- 
portant in  this  connection  are  the  recent  more  detailed 
studies  by  Cannon  and  others,  of  the  physiological  re- 
sponses. James,  after  all,  left  the  statement  of  the 
nature  of  the  bodily  responses  in  very  general  form.  He 
did  not  attempt  to  determine  what  bodily  organs  were 
involved  in  the  complex  response  but  was  content  to 
let  each  man  observe  them  for  himself.  One  by  one 
experimenters  have  added  to  the  list  of  known  changes 
and,  while  it  still  cannot  be  regarded  as  complete,  we 
have  definite  evidence  of  a  large  number.  Among  the 
first  discovered  were  changes  in  the  digestive  tract. 
Strong  emotional  excitement  checks  the  flow  of  saliva 
and  of  the  digestive  fluids  in  stomach  and  small  intes- 


BODILY  RESPONSE   IN   EMOTION  309 

tine  as  well  as  the  peristaltic  movements  of  the  whole  ali- 
mentary canal.  One  may  observe  directly  the  dryness 
of  the  mouth  in  fear  or  grief  and  the  increased  flow  of 
saliva  in  various  pleasurable  states.  The  disturbances  in 
the  alimentary  tract  are  the  cause  of  the  discomfort  that 
follows  eating  when  much  excited,  and  can  be  directly 
observed  in  animals  under  experimental  conditions. 
These  changes  prepare  the  animal  for  exertion  by  with- 
drawing the  blood  from  the  abdomen  for  use  in  the 
muscles,  the  organs  directly  involved  in  action. 

Adrenal  Secretion  in  Emotion.  —  Still  more  striking 
are  the  recently  discovered  activities  of  the  adrenal 
bodies  whose  function  it  is  to  secrete  into  the  blood  a 
chemical  known  as  adrenin.  Cannon  has  shown  that 
the  substance  is  present  in  increased  quantities  during 
intense  emotion  of  any  kind.  The  presence  of  adrenin 
has  three  effects,  (i)  It  causes  the  liver  to  release  its 
stored  glycogen  or  sugar,  which  provides  an  easily 
assimilable  food  for  the  muscles  and  other  tissues. 

(2)  It  increases  the  tendency  of  the  blood  to  coagulate. 

(3)  It  produces  a  constriction  of  the  small  blood-vessels. 
These  together  prepare  the  body  for  vigorous  action. 
The  glycogen  rapidly  restores  the  fatigued  muscle,  and 
the  constriction  of  the  vessels  increases  the  blood  pres- 
sure and  thus  increases  the  irrigation  of  the  muscle  by 
the  blood.    This   washes   away   the   fatigue  products 
more  rapidly  and  so  diminishes  the  effects  of  fatigue. 
The  increased  coagulability  and  the  constriction  of  the 
blood-vessels  diminish  bleeding  in  case  wounds  result 
from  the  fighting  which  usually  follows  emotion  in  ani- 
mals.    One  may  look  upon   the  entire  group  of  re- 


310        THE  ESSENTIALS  OF  PSYCHOLOGY 

sponses  as  factors  in  the  preparation  of  the  body  to 
meet  the  demands  of  a  crisis  and  the  emotion  as  the 
awareness  of  these  changes. 

Responses  Common  to  Pleasant  and  Unpleasant 
Emotions.  —  One  result  of  these  experiments  is  not 
altogether  in  harmony  with  the  James  theory  of  emotion. 
That  is  that  approximately  the  same  effects  are  produced 
by  pleasant  and  unpleasant  emotions.  Secretion  of 
adrenalin  is  increased  both  in  the  dog  that  attacks  a 
cat  safely  protected  in  a  cage  and  in  the  cat.  Fear 
and  anger  induce  the  same  effect.  In  man  the  excited 
spectators  of  a  football  game  show  an  increase  of  glycogen 
just  as  do  the  contestants  or  as  do  students  taking  a 
severe  examination.  The  changes  in  Jbreathing^Lnd, 
circulation  are  identical  in  pleasure  and  in  displeasure. 
Secretion  of  tears  is  also  increased  both  by  pleasant  and 
unpleasant  experiences.  The  reactions  of  the  alimen- 
tary tract  probably  take  opposed  forms  in  mild  emotions 
of  the  two  types,  but  on  the  whole  these  fundamental 
physiological  responses  can  be  looked,  to  only-  Jor- the 
source  of  some  conscious  process  common  to  all  emo- 
tions. For  the  physical  correlates  of  the  mental  quali- 
ties which  characterise  different  emotions,  one  must 
look  to  the  more  external  voluntary  muscles.  The  facial 
expression  certainly  differs  from  emotion  to  emotion  and 
probably  similar  differences  may  be  found  in  the  muscles 
of  the  trunk.  One  must  then  think  of  the  emotion  as  a 
response  of  the  organism  to  a  critical  situation,  a  situa- 
tion which  offers  possibilities  of  great  benefit  or  of 
serious  injury.  This  situation  arouses  a  mass  of  in- 
stinctive responses.  One  group  ,of  JLhese  prepares  the 


EMOTION  AND   IMPULSE  31! 

body  to  meet  the  particular  situation  and  may  be  re- 
garded as  characteristic  of  the  situation.  The  other 
prepares  for  action  of  any  type,  —  increases  the  ca- 
pacity of  the  organism  in  general.  The  first  varies  as 
the  situation  demands  running  or  fighting,  as  the  out- 
come promises  well  or  ill,  and  is  accompanied  by  a 
consciousness  that  changes  with  each  element  in  the 
situation.  The  second  group  is  common  to  all  emotions 
and  its  mental  accompaniment  is  excitement  which  is 
also  common  to  all  emotions. 

Distinction  between  Emotion  and  Impulse.  —  One 
further  limitation  of  the  definition  of  emotion  as  the 
consciousness  that  accompanies  an  instinctive  response 
is  that  in  the  emotion  the  movement  has  no  end  out- 
side of  the  body,  while  in  instinct  proper  the  end  of  the 
action  is  to  be  found  in  the  world  without.  Anger  is 
anger  in  the  strictest  sense  only  when  the  emotion  is 
not  vented  on  the  object.  Fear  is  fear  in  this  sense 
only  so  long  as  the  contractions  are  restricted  to  the 
body  of  the  man  in  fear.  Flight  ordinarily  relieves  the 
fear  and  is  classed  as  an  impulse  rather  than  as  an 
emotion.  If  we  bring  together  the  characteristics  of 
the  emotions,  we  find  that  they  are  distinguished  from 
the  feelings  by  the  fact  that  emotion^is  always  a^oinrjlex 
response  to  a  very  complicated  situation,  while  the  feel- 
ing  is  relatively  simple  and  aroused  by  a  single_stimulus. 
A  pin  prick  is  unpleasant,  but  if  on  examination  you 
find  that  one  whom  you  do  not  like  is  pricking  you, 
you  become  angry.  Emotion  nevertheless  usually  con- 
tains something  of  pleasure  or  displeasure.  ^Emotions 
are  distinguished  from  instincts  or  impulses  by  the  lack 


312        THE  ESSENTIALS  OF  PSYCHOLOGY 

of  objective  end  for  the  action,  —  the  movements  are 
confined  to  vague  contractions  of  the  body  muscles. 
An  emotion  is  related  to  both  feeling  and  impulse,  and 
at  the  extremes  may  easily  be  distinguished  from  either, 
although  the  exact  line  of  division  is  not  always  easy  to 
draw. 

The  Origin  of  Emotional  Expression.  —  Much  interest 
attaches  to  the  problem  of  why  the  movements  in  emo- 
tion take  the  course  they  do.  The  responses  are  common 
to  all  races  and  to  most  individuals,  in  spite  of  the  fact 
that  many  seem  to  have  no  great  utility.  Darwin  pro- 
posed a  theory  in  his  "  Expression  of  the  Emotions  in 
Animals  and  Man  "  that  is  still  as  satisfactory  as  any 
that  we  have.  He  based  his  explanation  upon  the 
assumption  that  all  facial  and  bodily  expressions  must 
be  regarded  primarily  as  survivals  of  once  useful  move- 
ments, whose  usefulness  has  disappeared.  In  the  early 
stages,  crying  makes  for  the  preservation  of  the  child, 
because  it  attracts  attention  when  it  is  lost,  or  when 
injured  or  otherwise  in  need  of  assistance.  The  re- 
sponse persists  after  it  has  ceased  to  be  useful.  Aside 
from  expressions  that  have  been  directly  useful  at  some 
time  in  the  development  of  the  species,  there  are  trans- 
fers of  expressions  from  the  original  connection  to  others 
in  which  they  are  useless.  Darwin  recognised  two  prin- 
ciples of  transfer.  First,  expressions  that  have  once  been 
useful  in  a  given  connection  are  transferred  to  other 
similar  emotions.  The  sneer  of  a  man  is  the  remnant 
of  the  unsheathing  of  the  teeth  in  an  animal.  The  man 
feels  as  the  dog  does  in  preparing  for  the  attack.  He 
expresses  himself  in  the  same  way,  although  it  is  no 


EVOLUTION   OF   THE   EMOTIONS  313 

longer  customary  to  fight  with  the  teeth.  The  nod  of 
affirmation  is  a  metaphor  that  has  been  transferred 
from  the  motion  of  the  head  that  the  child  makes  in 
taking  food  into  the  mouth ;  the  shake  of  the  head  in 
negation,  a  transfer  from  the  child's  act  in  moving  the 
head  quickly  to  avoid  taking  unwelcome  food  into  the 
mouth.  Darwin's  second  principle,  that  opposed  emo- 
tions are  expressed  in  opposite  ways,  is  of  rather  less 
general  application.  His  best  instance  is  the  expression 
of  delight  or  friendliness  in  the  cat.  When  the  cat  is 
angry,  it  lashes  its  sides,  and  crouches  for  the  attack  so 
that  it  is  as  inconspicuous  as  possible.  When  pleased, 
the  attitude  is  just  the  reverse,  —  the  back  is  arched, 
the  tail  is  held  erect,  and  everything  is  as  conspicuous 
as  possible.  In  addition  Darwin  has  a  group  of  ex- 
pressions left  unexplained  which  he  refers  to  the  mere 
nervous  overflow  —  for  instance,  the  turning  grey  of 
the  hair  from  fright  (if  the  fact  be  accepted),  and  the 
standing  on  end  of  the  hair.  Of  these  principles,  the 
second  and  third  seem  less  well  established.  The  meta- 
phorical transfer  of  emotional  expression  is  accepted  in 
some  form  by  practically  all  and  has  many  applications. 
The  more  general  principle,  that  expression  is  the  sur- 
vival of  instinctive  responses  that  were  once  valuable, 
is  fundamental  to  all  theories.  The  expressions  are 
slight  remnants  of  movements  once  important  for  the 
survival  of  the  individual  in  the  circumstances  which 
now  call  out  the  emotion. 

The  Classification  of  Emotions.  —  The  problem  of 
the  classification  of  emotions  has  occupied  philosophers 
and  psychologists  since  Descartes,  and  no  entirely  satis- 


314        THE  ESSENTIALS  OF  PSYCHOLOGY 

factory  grouping  has  yet  been  made.  This  is  partly 
because  there  are  a  number  of  different  principles  of 
division  that  cut  across  each  other,  partly  from  mere 
lack  of  knowledge.  Since  the  emotions  are  the  sub- 
jective  side  of  instinct  and  at  the  same  time  definite 
bodily  responses,  one  might  base  a  classification  either 
upon  the  instincts  or  upon  the  bodily  reactions.  Neither 
is  quite  satisfactory  since  the  bodily  responses,  so  far 
as  known,  are  frequently  the  same  for  more  than  one 
instinct,  and  the  instincts  are  classified  on  the  basis  of 
the  ends  they  subserve  rather  than  by  the  nature  of  the 
responses.  The  general  lines  may  be  suggested.  Three 
definitely  distinct  emotional  expressions  are  found  in 
love,  anger,  and  fear.  One  is  pleasant,  the  other  two 
unpleasant;  and  of  the  latter  fear  is  passive,  anger, 
active.  These  fundamental  emotions  vary  in  quality 
as  they  are  aroused  by  different  stimuli  or  subserve 
different  ends.  Thus  fear  is  different  from  disgust  and 
shame,  both  in  the  reference  and  in  the  bodily  response ; 
jealousy  in  the  same  way,  from  anger,  and  pride  and 
joy,  from  love.  Anger  is  different  from  rage,  in  the 
intensity  of  the  emotion.  Some,  as  shame  and  pride, 
have  a  subjective  reference,  while  fear  and  love  have 
an  objective.  Again  we  classify  in  language  with  refer- 
ence to  the  time  of  the  event  that  arouses  the  emotion. 
Thus  dread  and  hope  are  the  future  forms  of  fear  and 
love,  respectively ;  regret  and  satisfaction,  the  past 
forms.  Language  supplies  many  minor  shadings  which 
are  difficult  to  fit  into  any  logical  scheme.  Another 
difficulty  in  the  practical  classification  of  one's  own 
emotions  is  found  in  the  fact  that  emotional  response 


EMOTION   AND   EXPRESSION  315 

to  the  same  situation  varies  greatly  with  the  intellectual 
attitude  toward  it  and  this  changes  often  while  the 
situation  remains  the  same.  Hope  changes  to  fear  and 
fear  to  anger  in  rapid  alternation.  When  one  recalls 
the  situation  one  is  apt  to  overlook  the  changes  and 
call  the  whole  response  one  emotion,  —  which  one  de- 
pends upon  the  final  outcome. 

Emotional  Control.  —  Control  of  emotion  or  of  emo- 
tional expression  is  largely  in  terms  of  the  attitude  one 
takes  toward  the  stimulus  or  sensation.  A  caress  from 
one  person  may  please  or  be  a  matter  of  indifference, 
from  another  may  cause  anger;  what  occasions  anger 
in  one  mood  may  give  pleasure  in  another  mood  or 
attitude.  The  attitude  is  in  large  measure  under  one's 
control.  From  the  nature  of  the  organism  and  its  in- 
heritance, certain  objects  or  stimuli  must  call  out  one 
response,  and  one  alone.  But  aside  from  these  most 
fundamental  instincts  invariably  evoked  by  certain 
stimuli  alone,  sensations  and  stimuli  are  susceptible  of 
different  classifications,  and  when  classified,  arouse  the 
emotion  that  belongs  to  the  class.  Whether  a  remark 
falls  into  the  group  of  jests  or  of  insults  is  often  largely 
a  matter  of  chance,  and  dependent  upon  circumstance. 
The  emotions  may  be  controlled  only  in  so  far  as  it  is 
possible  to  vary  the  classification  of  the  stimulus.  The 
classification  depends  very  largely  upon  how  one  attends. 

Does  Expression  Relieve  Emotion?  —  One  frequently 
hears  the  statement  that  free  expression  relieves  or  re- 
duces an  emotion,  while  a  pent-up  anger  or  grief  grows 
stronger.  There  is  some  evidence  that  a  '  good  cry  ' 
assuages  grief.  Of  interest  in  this  connection  is  a  theory 


316        THE  ESSENTIALS  OF  PSYCHOLOGY 

of  the  Austrian  physician  Freud  that  many  of  the  dis- 
turbances of  mental  life  come  from  conflict  between 
emotions  that  leads  one  instinct  to  suppress  another. 
A  recent  report  of  Rivers  on  the  nervous  disturbance 
of  shell-shock  would  trace  the  origin  of  the  disease  to  a 
conflict  between  the  natural  instinct  of  fear  and  the 
social  pressure  that  prevents  a  man  from  showing  it. 
Curious  paralyses  and  disturbances  of  sensation  that 
prevent  a  man  from  subjecting  himself  to  danger  some- 
times present  themselves  in  these  cases.  Eder  quotes 
the  case  of  an  Australian  soldier  at  Gallipoli  who  was 
firing  through  an  embrasure  when  bullets  struck  several 
times  near  his  head.  He  could  no  longer  see  with  his 
right  eye,  although  the  tissues  were  perfectly  normal.  It 
was  interpreted  as  an  instinctive  protest  against  further 
danger.  Whether  we  accept  all  of  the  phases  of  the 
Freud  theory  or  not,  it  seems  probable  that  many  of 
these  disturbances  can  be  traced  to  such  conflicts  in 
emotional  tendency. 

Can  Conflict  and  Repression  be  Avoided?  —  It  has 
been  argued  from  these  theories  and  facts  that  all  con- 
flict in  instincts  should  and  possibly  could  be  avoided. 
We  are  told  that  a  child  should  always  be  permitted  to 
act  out  his  instincts  and  that  he  should  never  be  com- 
pelled to  suppress  the  emotional  expression  that  corre- 
sponds to  them.  This  recommendation  is  an  ideal,  but 
one  which  can  seldom  be  attained  in  ordinary  practice. 
Were  one  to  consider  the  individual  alone  and  then 
only  to  insure  perfect  mental  health,  the  prescription 
would  probably  provide  a  means  to  that  end.  But  the 
fact  that  individuals  live  in  society,  and  that  the  social 


THE   EMOTIONS  317 

Instincts  conflict  with  the  individual  makes  complete 
compliance  with  the  rule  impossible.  Certain  emo- 
tional conflicts  are  necessary.  There  are  many  cases 
in  which  others  would  suffer  did  the  individual  vent 
his  emotions  freely  and  the  individual  who  must  live 
in  society  would  suffer  did  he  form  the  habit  of  dis- 
regarding others  completely.  In  practice,  one  learns 
to  compromise  emotional  conflicts.  So  much  of  the 
rule  may  be  followed  as  implies  not  raising  unnecessary 
conflicts  for  the  child  or  for  one's  self.  The  puritan 
rule  that  one  should  practise  self-denial  for  the  sake  of 
moral  training  and  against  the  time  when  necessity 
for  repression  may  arise  may  well  be  disregarded  in 
favor  of  avoiding  conflict,  but  in  the  many  cases  in 
which  essential  desires  and  emotions  conflict,  discipline 
must  be  maintained,  the  social  forces  must  be  given  a 
hearing. 

Self-Control.  —  A  large  part  of  what  is  ordinarily 
•called  self-control  is  really  "control  "of"  the  emotions. 
Lack  of  self-control  arises  from  conflict  of  emotions, 
and  of  the  ideals  and  instincts  that  cause  emotions. 
Usually  either  one  has  disagreeable  emotions  that  are 
unnecessary  or  expresses  too  freely  the  emotions  that 
one  does  have.  Unnecessary  discontent  arises  from 
failure  to  attain  to  one's  ideal  standard  and  this  may 
be  due  either  to  having  too  high  ideals,  or  in  not  work- 
ing hard  enough  to  attain  them  and  then  wasting  effort 
in  regret  that  might  better  have  been  spent  on  accom- 
plishment. It  is  necessary,  too,  to  keep  in  mind  human 
limitations  and  so  not  to  expect  too  much  of  one's  self. 
A  cure  for  any  of  these  evils  is  not  emotional  repression, 


318        THE  ESSENTIALS  OF  PSYCHOLOGY 

but  elimination  of  the  fundamental  causes.  The  cure 
is  to  be  found  either  in  reducing  one's  ideals  or  increasing 
one's  accomplishment  by  better  methods  of  work.  To 
reduce  ideals  is  difficult,  more  difficult  than  one  thinks. 
If  it  were  too  successful  it  would  reduce  efficiency  by 
diminishing  effort.  A  well-balanced  soul  may  attain 
the  same  end  by  accepting  the  difficulties  and  at  the 
same  time  striving  for  the  end.  To  regard  all  effort  as 
part  of  the  day's  work,  with  no  stigma  attaching  to 
failure  and  not  too  much  credit  coming  from  success, 
is  the  ideal  attitude,  although  if  not  in  harmony  with 
temperament  it  can  be  attained  only  as  a  result  of  long 
habit.  Even  in  this  prescription  there  is  danger  that 
it  may  lead  to  a  cynical  depreciation  of  the  advantages 
of  success  that  destroys  ideals  or  on  the  other  hand  that 
it  may  merely  repress  the  emotion,  either  as  a  pose  that 
will  have  unpleasant  social  consequences,  or  if  the  re- 
pression be  real  that  it  may  incur  the  dangers  empha- 
sised by  Freud. 

The  other  alternative  is  to  permit  one's  self  free  ex- 
pression at  all  times,  to  be  perfectly  ready  to  face  the 
facts  and  willing  to  experience  the  emotion  that  logically 
or  instinctively  follows  from  them.  Where  one  is  deal- 
ing with  misfortunes  that  are  real  and  inescapable  as 
in  the  death  of  relatives  and  friends  or  the  loss  of  one's 
health  and  capacity  for  work,  free  expression  is  the  only 
rule.  Here,  too,  the  emotion  may  be  diminished  by 
occupation  of  mind  and  body  which  will  distract  from 
the  emotion.  In  certain  cases  the  emotion  may  be 
transformed  and  find  a  useful  outlet  in  something  that 
symbolises  one's  own  grief  as  in  charitable  work.  The 


EMOTIONAL  CONTROL  319 

usual  rule  of  looking  on  the  bright  side  has  much  to 
recommend  it,  provided  only  that  it  does  not  lead  to 
falsification  of  the  event  and  so  store  up  new  troubles 
for  the  time  of  realisation  or  lead  to  suppression  and 
the  consequent  mental  and  physical  ills.  Usually  a 
grief  boldly  faced  yields  to  the  development  of  new 
habits  that  replace  the  old  ones  disturbed  by  the  mis- 
fortune, and  the  formation  of  new  ideals  and  complete 
readjustment  follows.  Readjustment  must  come  some 
time  and  the  sooner  the  better.  Perfect  honesty  with 
one's  self  as  with  others  is  best  in  this  field  as  in  all 
others. 

Transfers  of  Emotional  Response.  —  That  reactions 
may  be  carried  over  from  one  situation  to  others  similar 
to  or  in  some  way  connected  with  it  is  proved  by  experi- 
ment and  by  observation  in  normal  and  abnormal  in- 
dividuals. The  Russian  physiologist  Pawlow  obtained 
evidence  of  these  transfers  in  a  number  of  striking 
experiments  on  dogs  in  which  he  used  accurate  measure- 
ments of  the  secretion  of  saliva  as  an  indication  of  the 
emotions.  As  is  familiar  to  every  one,  sight  of  food 
starts  a  secretion  of  saliva.  If  the  food  was  given  a 
few  times  simultaneously  with  the  striking  of  a  bell, 
the  sound  of  the  bell  alone  came  to  evoke  the  secretion. 
Evidence  of  similar  transfers  is  abundantly  supplied 
from  common  experience.  Much  of  the  pleasure  or 
its  opposite  obtained  from  the  articles  of  daily  use  is 
derived  from  their  associations.  So  marked  and  so 
frequent  are  these  transfers  in  the  mentally  abnormal 
that  one  school  of  psychiatrists  sees  in  them  the  prime 
evidence  of  mental  disease.  The  disturbances  are  con- 


320  THE  ESSENTIALS   OF   PSYCHOLOGY 

nected  with  emotions  aroused  by  memories  of  early 
crises,  but  the  memories  themselves  frequently  do  not 
come  to  full  consciousness ;  they  are  assigned  to  objects 
that  have  become  symbols  of  the  event.  Thus  in  one 
case  reported  by  Dr.  Morton  Prince,  a  woman  was  pro- 
foundly depressed  by  the  sound  of  church  bells  and 
could  not  account  for  the  effect.  Careful  examination 
by  special  methods  disclosed  the  fact  that  the  sound 
had  been  closely  related  to  the  death  and  burial  of  her 
mother,  which  had  occurred  under  peculiarly  distressing 
circumstances.  Such  instances  of  transfer  of  emotion 
from  one  object  or  event  to  others  only  indirectly  re- 
lated to  them  in  the  life  of  individuals  are  suggestive 
of  the  possibility  of  a  similar  transfer  of  expressions 
from  one  event  to  others  of  the  same  class  during  the 
long  course  of  evolution. 

Emotions  Dependent  upon  Intellectual  Appreciation. 
—  Not  all  emotions  can  be  explained  directly  by  this 
theory  of  instinctive  response.  Certain  emotions,  it  is 
true,  come  without  preliminary  consciousness  and  the 
response  may  be  contrary  to  desire  or  even  opposed  to 
all  rational  expectations.  James'  fainting  at  the  sight 
of  blood  is  typical  of  this  class.  For  them  the  theory 
outlined  suffices.  But  we  have  many  emotions  which 
arise  only  after  interpretation,  which  are  influenced  by 
contemplation  as  much  as  by  the  stimulus.  Many 
times  one  does  not  become  angry  until  one  sees  who  is 
playing  the  trick;  one  is  not  afraid  until  the  full  list 
of  circumstances  is  taken  into  consideration.  One  sees 
a  snake  and  at  first  feels  only  curiosity.  Later  when 
the  markings  are  noted  or  the  rattle  on  the  tail,  one 


EMOTION  AND   INTELLECT  32! 

begins  to  grow  cold,  to  shiver,  to  feel  a  sinking  in  the 
abdomen,  and  all  of  the  other  symptoms  of  fear.  The 
reflection .upon  the  stimulus,  not  the  stimulus  itself^ 
seems  to  be  the  cause  of  the  reaction.  This  does  not 
mean  that  the  bodily  response  is  not  an  essential  part 
of  the  emotion,  even  that  it  is  not  the  most  important 
element  in  colouring  the  emotion;  but  it  does  mean 
that  in  addition  to  the  instinctive  contractions  or  as  a 
cause  of  these  contractions,  one  must  consider  the  wider 
intellectual  setting  if  one  is  to  give  a  full  explanation. 

The  Intellectual  Emotions.  —  Two  classes  of  emotion 
may  be  distinguished  in  which  these  intellectual  factors 
are  important.  In  one,  interpretation  consists  in  re- 
ferring the  stimulus  to  a  known  class.  When  the  refer- 
ence is  completed,  the  instinctive  response  is  immediate. 
Fear  of  the  snake  or  anger  at  the  trick  is  delayed  until 
the  reference  is  made,  until  the  situation  is  understood, 
then  the  instinctive  response  comes  at  once.  In  the 
second  class  the  situation  threatens  no  immediate  danger, 
and  promises  no  immediate  benefit  and  the  response 
could  never  have  been  of  survival  value  in  a  similar 
situation  in  the  pre-human  stages  of  evolution.  MOSJL 
of  our  emotions  in  peaceful  civilised  life  are  evoked  by 
winning  or  losing  prizes  of  symbolic  value  only.  One 
is  elated  over  school  or  social  honors,  one  worries  at 
loss  of  money  or  of  the  social  prestige  that  goes  with 
money,  one  grows  angry  at  deprecatory  remarks  about 
one's  self  or  one's  family.  No  one  of  these  can  be  ex- 
plained directly  as  vestjgial  instinctive  responses  once 
of  value  in  protecting  the  individual.  -  Itjs__the_jcuk 
that  emotions  are  now  due  to  success  or  failure  in  the 

Y 


322        THE  ESSENTIALS  OF  PSYCHOLOGY 

Attainment  of  ideals  established  by  social  convention^. 
Originally  they  might  have  been  connected  with  the 
attainment  of  ends  of  survival  value,  but  in  many  cases 
the  connection  has  become  very  remote.  The  organic 
response  in  these  must  be  thought  of  as  transferred 
from  a  similar  situation  in  which  it  was  fitting.  In  our 
present  life  situations  seem  to  have  been  grouped  into 
conventional  classes,  each  class  with  its  appropriate 
response.  Unjust  deprivation  of  anything  becomes  a 
cause  of  anger  and  the  response  always  comes,  it  matters 
not  whether  the  thing  of  which  one  is  deprived  is  a  dinner 
or  an  intangible  something  regarded  as  an  element  in 
the  total  reputation.  The  insinuation  that  a  pet  theory 
is  not  all  that  one  has  thought  it  may  cause  as  violent 
a  reaction  as  a  physical  injury.  The  transfer  of  the 
response  from  situations  where  they  might  be  of  value 
to  those  only  remotely  similar  may  be  regarded  as  meta- 
phorical and  as  expressions  of  Darwin's  first  law  men- 
tioned above.  Iru  discussing  emotion,  then,  we  must 
consider  the  knowledge  and  ideals  of  the  individual  as 
well  "as" his  instincts.  Emotional  responses  are  evoked 
by  a  total  situation  in  the  light  of  intellectual  apprecia- 
tion  rather  than  constituting  instinctive  responses  to  a 
single  stimulus.  With  this  addition,  emotion  may  be 
defined  as  the  awareness  of  the  instinctive  response. 
It  is  the  consciousness  of  the  reaction  of  the  individual 
as  a  whole  to  the  situation  as  a  whole. 

Mood.  —  Closely  related  to  emotion  are  mood  and 
temperament.  Two  uses  of  the  word  mood  must  be 
distinguished.  The  first  designates  an  emotion  of  long 
duration  and  of  slight  intensity.  A  mood  is  an  affair 


MOOD   AND    TEMPERAMENT  323 

of  hours  or  days.  In  the  second  sense  mood  is  rather  a 
predisposition  to  an  emotion  or  group  of  emotions  than 
the  actual  emotion  itself  of  which  one  may  not  even 
be  conscious  until  the  emotion  comes.  Usually,  how- 
ever, one  is  conscious  of  the  predisposition  in  advance 
of  the  emotional  outburst.  So  one  finds  one's  self  in  a 
cheerful  mood  in  which  everything  pleasant  has  a 
definite  appeal,  or  in  a  depressed  or  angry  mood  in 
which  anything  whatever  is  likely  to  arouse  an  emotion 
of  anger  or  a  state  of  depression.  One  is  '  set '  for  an 
emotion  of  one  kind  or  of  one  general  class,  and  as  a 
consequence  it  is  very  much  easier  than  usual  to  arouse 
an  emotion  of  that  class.  At  times  one  has  an  incipient 
emotion  with  no  apparent  cause.  One  may  feel  mildly 
cheerful  during  a  day  in  advance  of  any  emotion  and 
irrespective  of  particular  stimulus,  but  mood  is  not 
necessarily  conscious  in  advance  of  the  stimulus  that 
excites  the  emotion.  The  mood  may  owe  its  origin  to 
some  particular  stimulus  or  group  of  stimuli,  or  it  may 
be  due  to  the  state  of  health.  A  piece  of  good  fortune 
induces  a  pleasant  mood  that  for  a  long  time  makes 
pleasant  emotions  easy ;  any  misfortune  tends  to  reduce 
the  capacity  for  enjoyment  and  increases  the  liability  to 
disagreeable  emotions  over  a  period  of  hours  or  days.  On 
the  other  hand,  perfect  health  and  a  bright  day  are  suffi- 
cient to  induce  a  pleasant  mood,  while  nothing  is  so  con- 
ducive to  low  spirits  and  unpleasant  moods  as  bad  health. 
Temperament.  —  Temperament  is  a  mood  that  is 
permanent.  Individuals  are  born  apparently  with  ten- 
dencies to  look  on  the  bright  or  dark  side  of  life.  If  it 
is  not  certain  that  the  temperament  is  innate,  at  least  it 


324  THE   ESSENTIALS   OF   PSYCHOLOGY 

has  become  permanent  in  early  life  and  seldom  changes 
completely  after  maturity.  The  psychology  of  tempera- 
ments leaves  much  to  be  desired.  With  the  whole  of  the 
psychology  of  individual  differences,  it  has  received  more 
recognition  for  its  importance  than  labour  toward  its 
development.  One  may  pick  out  quite  easily  from  his 
acquaintances  individuals  who  are  particularly  prone  to 
emotions  of  one  kind  or  another,  but  to  determine  what 
the  most  striking  features  of  the  temperaments  are  and 
to  group  them  in  a  satisfactory  way  is  by  no  means  so 
easy.  Psychology  is  still  accustomed  to  make  use  of 
the  classes  of  the  ancients,  —  phlegmatic  and  sanguine, 
melancholic  and  choleric.  This  classification  is  modified 
by  Wundt  to  designate  the  strength  and  quickness  of 
the  individual,  not  the  permanent  mood  or  susceptibility 
to  emotions.  The  sanguine  individual  combines  quick- 
ness with  weakness ;  the  choleric,  quickness  with 
strength ;  the  melancholic  is  slow  and  weak ;  the 
phlegmatic,  slow  and  strong.  While  these  qualities  are 
the  only  ones  made  explicit  by  the  classification,  there 
is  implied  in  the  terms  as  ordinarily  used  a  predisposition 
to  different  emotions  and  tendencies  to  be  easily  pleased 
or  displeased.  The  melancholic  individual  is  un- 
doubtedly predisposed  to  grief  or  low  spirits,  as  is  the 
sanguine  individual  to  pleasant  emotions.  The  choleric 
individual  is  predisposed  to  anger,  as  the  phlegmatic  to 
calm,  even  amid  temptations  to  excitement.  This 
classification,  old  as  it  is,  can  be  regarded  as  no  more 
than  a  beginning  in  the  study  of  individual  differences. 
Much  more  remains  to  be  done  and  could  be  done  with 
relatively  little  difficulty.  It  is  sufficient  to  indicate 


THE  EMOTIONS  325 

that  men  are  differently  disposed  toward  different  emo- 
tions, and  that  some  respond  easily,  others  with  difficulty. 
JWhat .  emotion  shall  be  excited  depends  fully  as  much 
upon  the  individual  as  it  does  upon  the  stimulus. 

EXERCISES 

1.  Give  an  instance  of  an  emotion  and  of  a  feeling.    How  are 
they  different  ? 

2.  Recall  some  strong  emotion.    How  did  it  affect  the  accuracy 
of  your  thinking  ?    The  efficiency  of  your  acts  ? 

3.  What  are  the  characteristics  of  the  James  theory?     Can 
you  think  of  any  objections  to  it  ? 

4.  Can  you  recall  any  instance  of  true  emotion  without  bodily 
reactions  ? 

5.  How  are  the  motor  responses  in  anger  different  from  those  in 
fear?    In  joy  from  those  in  hate ? 

6.  Distinguish  the  physiological  effects  common  to  all  emotions 
from  others  peculiar  to  certain  emotions. 

7.  Do  the  bodily  expressions  precede  or  follow  the  emotion  as  a 
mental  process? 

8.  Can  the  emotion  or  its  expression  be  repressed  or  modified? 
Does  experience  change  the  original  character  of  the  emotion  or  its 
expression?    How  does  it  resemble  instinct  in  these  respects? 

9.  Why  does  sorrow  over  failure  to  win  a  social  honour  have  the 
same  bodily  expression  as  sorrow  over  losing  a  bit  of  food  ?    Why 
does  loss  of  a  sum  of  money  have  the  same  effect? 

10.  Describe  the  facial  expression  in  anger,  in  joy,  in  sorrow. 
Does  the  facial  expression  contribute  anything  to  the  quality  of  the 
emotion  ? 

REFERENCES 

JAMES  :  Principles  of  Psychology,  vol.  ii,  ch.  xxv. 

TITCHENER:  Text-book  of  Psychology,  pp.  471-503. 

ANGELL  :  Psychology,  chs.  xviii,  xix. 

JASTROW  :  The  Qualities  of  Men. 

CANNON  :  Bodily  States  in  Pain,  Hunger,  etc. 


CHAPTER  XIII 
ACTION  AND   WILL 

Action  the  End.  —  The  most  important  practical 
problem  in  psychology  is  the  control  of  action.  Almost 
all  thinking  and  very  much  of  feeling  and  emotion  are 
of  value  to  the  organism  only  as  they  lead  to  action  of 
some  sort  or  other.  Action  is  very  closely  related  to 
thought  and  feeling.  Much  of  action  grows  out  of 
thinking  and  we  appreciate  action  only  by  means  of 
the  sensory  processes.  As  was  asserted  in  connection 
with  the  discussion  of  the  nervous  system,  all  action  is 
sensori-motor ;  it  begins  in  sensation  and  ends  in  mus- 
cular contractions.  One  may  complete  the  circle  by 
the  assertion  that  when  the  muscles  contract,  they 
arouse  processes  in  the  sensory  ends  in  the  body  of  the 
muscle,  and  these  sensory  processes,  in  their  turn,  give 
the  only  evidence  to  consciousness  of  the  contraction 
of  the  muscle.  A  muscle  moves  only  on  the  excitation 
of  some  sensory  neurone,  either  directly  by  the  sense- 
organ  or  indirectly  by  memory,  and  the  movement  of 
that  muscle  can  be  known  only  through  the  stimulation 
of  the  sensory  ends  in  the  muscle  that  contracts. 

Evidently,  the  various  problems  in  connection  with 

action  are  problems  of  the  control  of  thoughts  and  of 

sensations,  and  of  the  connections  between  thoughts  and 

sensations,  and  actions.     The  classification  of  actions 

326 


CLASSIFICATION   OF   ACTION  327 

must  be  either  in  terms  of  the  accompanying  mental 
processes,  or  in  terms  of  the  nature  of  the  connection 
between  the  movements  and  the  ideas.  Each  of  these 
criteria  has  been  used  in  the  generally  accepted  clas- 
sification. In  terms  of  accompanying  consciousness, 
actions  are  classified  as  impulse,  reflex  act,  and  volun- 
tary act.  In  the  technical  psychological  vocabulary,  any 
movement  that  grows  out  of  sensation  or  memory  image 
is  called  an  impulse.  In  the  complete  impulse,  sensation 
is  followed  by  movement,  and  that  is  followed  or  ac- 
companied by  a  kinaesthetic  sensation  which  informs  the 
agent  that  he  is  moving  or  has  moved.  In  most  of 
the  frequently  repeated  movements,  consciousness  falls 
away.  Reflex  action  is  often  not  appreciated ;  both  the 
stimulus  that  calls  it  out  and  the  sensory  processes  that 
accompany  it  may  pass  unnoticed.  One  winks  without 
being  aware  of  it  or  of  its  stimulus.  In  other  instances, 
as  when  one  draws  back  the  hand  on  being  pricked  with 
a  pin,  one  is  conscious  of  the  stimulus  and  of  the  move- 
ment, but  only  after  the  response  has  been  made.  Reflex 
action  is  distinguished  from  impulse  by  the  fact  that  the 
conscious  accompaniments  either  disappear,  are  reduced 
in  number,  or  enter  consciousness  after  the  movement 
has  been  executed.  The  more  complicated  acts  may  all 
be  regarded  as  modifications  of  impulse.  Voluntary  acts 
arise  when  several  ideas  each  with  corresponding  im- 
pulses are  present.  In  consequence,  consciousness  is 
more  complicated  than  in  impulse.  Each  idea  has  its 
own  natural  outcome  in  movement,  and  each  of  these 
partial  movements  adds  something  to  the  total  con- 
sciousness. In  automatic  acts,  the  consciousness  that 


328        THE  ESSENTIALS  OF  PSYCHOLOGY 

at  first  accompanied  the  movement  has  disappeared, 
and  the  movement  is  run  through  without  definite 
knowledge.  This  is  true  of  walking,  talking,  and  of 
most  of  the  more  complicated  habits.  If  automatic 
acts  are  to  be  defined  as  impulses  that  have  lost  some  or 
all  of  their  conscious  accompaniments,  volitional  acts 
may  be  defined  as  acts  performed  after  a  conflict  of 
impulses.  The  consciousness  is  more  complicated  than 
in  the  impulse,  because  each  impulse  adds  something 
to  the  total  consciousness. 

One  may  define  acts,  however,  not  merely  in  terms  of 
the  accompanying  consciousness,  but  also  with  reference 
to  the  time  at  which  the  connection  between  thought 
and  action  was  established.  On  this  basis  impulses 
may  be  classified  as  inherited  and  acquired.  The 
former  are  due  to  connections  between  sensation  and 
movement  established  before  the  birth  of  the  individual. 
The  child  is  born  with  the  synapses  between  certain 
sensory  regions  and  certain  motor  regions  already 
open.  Inherited  impulses  may  be  divided  again  into 
reflexes  and  instincts.  As  was  said  earlier,  reflexes  are 
simple  and  can  be  understood  in  terms  of  the  mere 
physiological  connections,  while  instincts  are  more  com- 
plex and  at  present  can  be  explained  only  through  an 
appeal  to  their  purpose.  Acquired  impulses,  on  the 
other  hand,  are  only  potentially  represented  in  the  in- 
dividual at  birth ;  they  are  the  outcome  of  connection? 
made  or  confirmed  by  action  during  the  life  of  th 
individual.  If  we  combine  the  results  of  the  two  clas- 
sifications, we  find  that  inherited  impulses  are  more 
likely  to  be  unaccompanied  by  consciousness  than  are 


THE   ACQUISITION   OF   MOVEMENTS  329 

acquired,  although  acquired  impulses  with  practice 
rapidly  lose  their  conscious  accompaniments.  It  should 
be  remarked  that  movements  are  always  excited  by 
sensory  stimuli,  whether  these  are  conscious  or  not,  and 
that  there  are  always  many  more  stimuli  involved  in  the 
control  of  the  movement  than  are  conscious. 

New  Movements  Learned  by  Trial  and  Error.  —  Ob- 
viously, the  first  problem  in  connection  with  movements 
is  to  determine  the  methods  by  which  they  may  be 
learned.  The  first  experiments  on  learning  that  proved 
fruitful  were  performed  on  animals.  An  animal  was 
confined  in  a  box,  provided  with  a  door  closed  by  some 
simple  device,  and  the  methods  by  which  the  animal 
learned  to  get  out  were  recorded.  The  results  demon- 
strated that  learning  was  by  chance.  The  cat  would 
struggle  vaguely,  trying  all  of  its  acquired  and  inherited 
responses  one  after  the  other.  It  would  bite  here, 
there,  and  everywhere,  would  scratch  at  each  projecting 
part  and  at  each  crevice,  until  finally  some  one  of  the 
movements  happened  to  open  the  door.  When  returned 
to  the  box  at  another  time,  it  would  run  through  the 
same  series  of  random  movements,  until  the  successful 
act  was  repeated.  Gradually  the  time  required  would 
become  shorter  until,  with  frequent  repetition,  the  sight 
of  the  cage  would  at  once  call  out  the  correct  response 
for  opening  the  door.  Nervously  this  means  that  the 
movement,  arising  at  first  by  chance,  is  established  by 
repetition.  The  synapse  traversed  frequently  by  this 
stimulus  may  be  pictured  as  becoming  more  and  more 
permeable,  until,  when  learning  is  complete,  the  sensation 
leads  at  once  to  the  appropriate  motor  discharge. 


330        THE  ESSENTIALS  OF  PSYCHOLOGY 

Human   Movements   also   Learned  by  Selection.  — 

The  same  general  law  has  been  shown  to  hold  as  well 
for  human  learning.  One  of  the  best  instances  of  this 
is  to  be  found  in  the  way  a  man  solves  a  mechanical 
puzzle.  He  may  merely  think  it  through  and,  after 
solving  it  in  thought,  test  the  solution  in  practice.  Even 
this  solution  in  thought  is,  as  was  seen  in  the  chapter 
on  Reasoning,  a  process  of  trial  and  error.  Suggestions 
appear  one  after  another  until  some  one  comes  that  is 
approved.  But  unless  very  familiar  with  other  forms 
of  puzzles,  he  will  proceed  just  as  the  cat  does  to  get  out 
of  a  box.  If  the  problem  is  to  take  apart  two  construc- 
tions of  wire,  he  will  try  to  put  one  through  each  place 
that  seems  possible,  and  will  keep  trying  until  he  suc- 
ceeds in  the  attempt.  When  he  gets  them  apart,  the 
chances  are  that  he  will  have  no  very  clear  idea  of  how  it 
was  done.  He  will,  at  most,  remember  in  a  vague  way 
the  point  of  least  resistance,  but  ordinarily  he  must  solve 
the  puzzle  more  or  less  accidentally  several  times  before 
he  can  remember  exactly  how  to  do  it  again,  or  be  able 
to  succeed  at  the  first  trial.  Practically  all  unfamiliar 
complicated  acts  are  performed  in  this  way.  Random 
movements,  with  stamping  in  of  the  accidental  success 
hrough  frequent  repetition,  is  the  universal  method  of 
human  as  well  as  of  animal  learning.  In  this  and  all 
similar  contexts  chance  movements  mean  movements 
of  unknown  cause.  Each  movement  made  is  determined 
by  the  external  stimulus  and  the  connections  established 
at  birth  or  acquired.  Where  we  cannot  trace  the  con- 
nections we  speak  of  them  as  made  by  chance. 

The  Child's  Learning.  —  This  law  is  illustrated  still 


THE   ACQUISITION   OF   MOVEMENTS  33! 

more  completely  by  the  child.  At  birth  the  movements 
of  the  child  are  all  pretty  well  tied  together.  When  the 
child  moves  one  hand,  the  other  moves  in  the  same  way 
and  about  as  far.  If  you  watch  the  feet,  you  will  see 
that  they  ordinarily  move  in  harmony  with  the  move- 
ments of  the  hand.  Any  stimulus  calls  out  many  more 
movements  than  are  needed.  Even  at  the  age  when  a 
child  learns  to  write,  the  different  members  are  still  more 
or  less  bound  together.  The  boy  follows  the  movements 
of  his  hand  by  sympathetic  rolling  of  his  tongue.  The 
process  of  learning  is  one  of  waiting  until  these  diffuse 
motor  discharges  bring  a  pleasant  result,  and  then  of 
repeating  the  movement  that  gave  that  result  until  it 
is  thoroughly  connected  with  the  appropriate  stimulus. 
After  this,  progress  in  learning  is  largely  a  matter  of 
separating  the  particular  element  desired  from  the 
complex  in  which  it  first  originated.  Learning  to  speak 
is  an  illustration  of  the  method.  The  child  of  six  months 
to  a  year  spends  much  of  its  comfortable  waking  time 
practising  vocal  exercises.  At  first  the  results  are  al- 
together indefinite  and  uncertain.  All  sorts  of  noises 
come  out  of  the  vocal  organs.  Whenever  one  that 
pleases  the  child's  fancy  makes  its  appearance,  it  is 
repeated,  more  or  less  accurately,  until  thoroughly 
learned.  Learning  words  follows  the  same  laws.  When 
a  sound  is  hit  upon  that  is  similar  to  a  word  uttered  by 
the  parents,  it  pleases  the  child.  It  is  repeated  and  the 
results  of  the  repetition,  in  the  pleasure  of  the  parents 
and  in  obtaining  the  satisfaction  of  its  desires,  serve 
to  increase  the  pleasantness  of  the  movement  and  to 
renew  the  struggles.  The  words  that  are  heard  do 


332        THE  ESSENTIALS  OF  PSYCHOLOGY 

not  serve  as  the  stimulus  for  their  repetition,  but  set  a 
pattern  toward  which  the  child  may  strive,  or  merely 
make  the  word  interesting  when  by  chance  it  is  uttered. 
Each  of  the  other  motor  accomplishments  is  acquired 
by  the  child  in  the  same  way. 

Learning  as  Transfer.  —  After  a  fair  number  of 
movements  have  been  learned,  the  first  attempts  at  a 
new  movement  are  more  nearly  successful.  If  the  child 
has  had  some  experience  with  a  pencil  in  drawing,  the 
first  attempts  at  writing  will  not  be  so  awkward  as  the 
first  attempts  at  drawing.  The  movements  will  all 
resemble  the  desired  result.  At  this  stage,  the  known 
movements  most  like  those  to  be  learned  will  be  used 
first.  Still,  the  method  of  modifying  the  old  to  obtain 
the  new  follows  the  same  laws  as  the  original  learning. 
One  first  makes  some  similar  familiar  movement,  and 
then  tries  to  vary  it  until  the  end  is  attained,  but  the 
modifications  are  struggled  for  in  the  same  random  way 
as  in  the  original  learning.  Many  trials  and  numerous 
discouraging  failures  are  usually  required  before  the 
desired  modification  presents  itself.  When  it  comes 
once,  it  can  be  called  out  a  second  time  only  after  nu- 
merous trials.  Each  success  makes  new  successes 
more  likely,  but  perfection  in  any  movement  comes 
slowly.  When  one  begins  to  learn  the  golf  stroke,  one 
ordinarily  has  a  number  of  similar  movements  at  com- 
mand. One  has  swung  an  axe,  or  has  cast  a  fly,  or 
practised  hitting  at  pebbles  with  a  stick.  One  calls 
upon  some  one  of  these  on  the  first  occasion  for  hitting 
the  ball.  The  probability  is  that  the  first  attempts  will 
be  inaccurate;  certainly  they  will  be  feeble.  The 


THE  ACQUISITION   OF   MOVEMENTS  333 

process  of  transforming  the  familiar  habits  into  adequate 
new  ones  is  one  of  constant  trial  and  slow  selection  of 
the  successful  variations.  In  the  more  complicated 
and  delicate  movements  of  this  sort,  one  frequently  does 
not  know  what  it  is  that  makes  the  stroke  successful. 
The  conscious  antecedents  of  the  successful  stroke  seem 
4o  be  very  little  different  from  those  present  in  the  un- 
successful, but  practice  brings  the  successful  stroke  more 
frequently.  Assuming,  then,  that  an  individual  has  a 
large  number  of  impulses  under  control,  whether  they 
have  been  established  by  earlier  practice  or  are  in- 
stinctive, we  find  that  new  movements  are  learned  by 
slow  and  painful  modification  of  these  responses. 

The  Acquisition  of  Skill.  —  Closely  related  in  explana- 
tion and  in  practice  to  the  learning  process  is  the  acquisi- 
tion of  skill.  When  one  has  mastered  trie  separate 
movements  necessary  for  the  accomplishment  of  some 
important  end,  the  process  of  combining  them  and  con- 
trolling them  in  such  a  way  as  to  give  rapid  and  accurate 
accomplishment  offers  much  that  is  of  interest  psycholog- 
ically, and  also  much  of  practical  importance.  Many 
investigations  have  been  made  of  the  methods  of  acquir- 
ing skill  in  telegraphy,  in  typewriting,  tossing  balls,  and 
in  various  other  games  and  occupations.  The  rough 
results  show  striking  agreement  among  the  different 
investigators,  and  for  different  sorts  of  learning.  Learn- 
ing has  a  characteristic  course.  One  may  represent  it 
by  curve  i,  showing  the  rate  of  learning  to  write  upon 
a  typewriter,  given  in  Figure  32.  It  will  be  seen  that 
progress  is  step-wise  all  through  the  test.  First,  there 
is  a  rapid  increase  in  skill  during  the  period  when  the 


334 


THE   ESSENTIALS   OF   PSYCHOLOGY 


elements  are  being  learned,  then  there  is  a  period  with- 
out progress,  then  another  rise,  and  so  on.  There  are 
alternations  of  rapid  improvement  with  levels  of  practice 


loo 

050 
IOOC 
950 
SOC 
650 
800 
750 
700 


650 


600 
550 
SOC 
450 
4QQ 
350 


A 


t 


FIG.  32.  —  Curve  of  learning  to  write  on  the  typewriter.  The  horizontal  dis- 
tance shows  the  days  of  practice;  the  vertical  line  the  number  of  words 
written  in  an  hour.  Curve  i  shows  the  progress  during  the  original  prac- 
tice ;  Curve  2,  the  results  of  nine  days'  practice  after  an  interval  of  two  years 
and  thirty-five  days.  (From  Swift:  'Memory  of  Skillful  Movements,' 
Psychological  Bulletin,  vol.  iii,  p.  186.) 


THE   ACQUISITION   OF   MOVEMENTS  335 

/ithout  improvement.  These  level  parts  of  the  curve 
have  been  called  the  plateaus.  It  should  also  be  noted 
that  in  the  first  part  of  the  experiment  the  curve  is  much 
steeper  than  later.  One  gradually  approaches,  but  never 
absolutely  reaches,  the  highest  performance  of  which 
the  individual  is  capable. 

The  Curve  of  Learning.  — The  mechanism  of  learning 
and  the  explanation  of  the  course  of  learning  are  also 
fairly  well  agreed  upon.  In  the  first  place,  methods  by 
which  improvement  is  made  are  seldom  conscious. 
One  falls  into  good  habits  and  gives  up  bad  habits  with 
no  knowledge  of  how  or  why.  The  man  does  his  best 
all  the  time,  and  at  times  he  improves,  at  times  he  con- 
tinues upon  the  same  level ;  he  himself  cannot  tell  how 
the  improvement  was  brought  about.  He  does  not 
ordinarily  plan  out  the  improvement ;  he  hits  upon  it  by 
chance.  More  interesting  and  consequently  more  dis- 
cussed is  the  explanation  of  the  plateaus  in  the  learning 
curve  and  the  occasion  for  rising  from  one  level  to 
another.  All  seem  to  agree  that,  during  the  period  of 
no  improvement,  associations  are  being  formed  that  are 
to  be  useful  at  a  later  stage  of  learning.  One  can  ad- 
vance to  a  certain  stage  only  on  the  basis  of  one  definite 
group  of  habits.  When  this  stage  has  been  reached,  no 
further  advance  is  possible  until  new  habits  have  been 
thoroughly  established.  During  the  time  one  keeps  to 
the  plateau  the  habits  are  being  stamped  in.  After  they 
have  been  thoroughly  established,  it  is  possible  to  go 
on  to  higher  acquirements.  Apparently,  the  learner 
works  just  as  hard  when  he  makes  no  progress  as  when 
he  is  advancing.  And  while  the  effects  of  the  work  do 


336         THE  ESSENTIALS  OF  PSYCHOLOGY 

not  show  in  the  accomplishments,  something  is  being 
gained  all  the  time  that  will  tell  finally  in  new  progress. 
Very  interesting  is  the  question  of  what  gives  the  sud- 
den rise  in  capacity.  Sometimes,  apparently,  it  is  the 
result  of  effort.  It  is  said  by  Bryan  and  Harter  that  a 
telegraph  operator  may  stay  for  years  at  a  small  office 
and  make  no  appreciable  gain  in  his  sending  or  receiving 
rate,  but  when  transferred  to  a  larger  office  where  more 
demands  are  made  upon  him,  he  will  suddenly  increase 
in  skill.  In  this  instance,  progress  is  the  result  of  effort, 
and  effort  of  increased  incentive.  But  effort  does  not 
always  lead  to  increased  accomplishment.  If  one  strives 
hard  for  a  new  advance  before  the  habits  are  ripe, 
the  result  usually  is  not  advantageous;  one  is  more 
likely  to  disturb  the  ordinary  habits  and  lose  efficiency 
than  to  gain  new  skill.  Effort  is  necessary  for  the  rise 
to  a  new  level  of  speed,  but  effort  is  harmful  before  the 
necessary  amount  of  preparation  has  been  made  by 
fixing  old  habits.  The  advance  may  be  accompanied 
by  relaxation  of  effort ;  the  work  seems  easier  when  the 
advance  begins.  Another  element  of  value  is  to  become 
clearly  aware  of  the  details  of  the  movements  that  are 
made  and  of  what  parts  are  essential.  It  is  the  rule,  in 
learning  new  and  effective  combinations,  that  they  are 
hit  upon  blindly,  and  only  later  become  consciously 
recognised.  With  the  recognition,  one  is  apparent!}- 
prepared  for  a  new  advance.  But  the  actual  improve- 
ment that  gives  the  advance  is  ordinarily  some  new 
chance  combination  that  develops  unintentionally,  and 
is  not  appreciated  when  it  comes.  In  some  cases  the 
plateau  seems  to  appear  when  certain  parts  of  the  com- 


THE    ACQUISITION   OF   MOVEMENTS  337 

plex  movement  are  being  learned  separately,  and  the 
sudden  rise  is  apparently  due  to  success  in  uniting  them 
into  a  single  whole.  Still  another  factor  that  is  probably 
as  important  as  the  acquirement  of  new  combinations  is 
the  disappearance  of  bad  habits.  Failure  to  advance 
may  be  due  to  the  persistence  of  some  unfortunate  habit 
acquired  early  in  the  task.  In  the  course  of  time  this 
bad  habit  may  disappear,  and  the  record  will  jump  up 
suddenly  to  a  new  level.  Both  the  development  of  a 
new  and  advantageous  habit  or  set  of  habits,  and  the 
disappearance  of  some  bad  habit  that  has  been  retarding 
advance  may  be  unnoticed.  They  are  not  planned  in 
advance  of  their  appearance,  and  are  not  recognised 
when  they  appear.  All  that  can  be  said  of  the  method 
of  acquiring  skill  is  that  one  must  continue  to  work  up 
to  his  best  capacity,  and  must  be  constantly  on  the  look- 
out for  any  new  method  that  may  promise  advance; 
but,  in  spite  of  one's  best  endeavour,  there  will  always  be 
periods  of  apparently  fruitless  effort,  plateaus  of  no 
advance,  and  the  advance  to  new  levels  will  come  un- 
expectedly and  for  no  assignable  reason. 

All  learning  is  by  the  same  law  of  chance  trials  and 
selection  of  the  suitable  movement  when  it  is  hit  upon  by 
chance.  The  first  learning  is  by  the  selection  of  move- 
ments connected  as  overflow  discharges  with  the  original 
instincts.  When  a  fair  number  of  these  have  been  fully 
established,  new  movements  are  acquired  by  chance 
variations  from  those  already  learned.  Finally,  when 
all  of  the  movements  involved  in  a  complicated  set  of 
activities  have  been  learned  and  one  desires  merely  to 
combine  them  in  the  best  possible  way  to  obtain  speed 
z 


338        THE  ESSENTIALS  OF  PSYCHOLOGY 

and  accuracy,  the  combinations  and  connections  are 
again  developed  by  chance.  Ordinarily  one  does  not 
know,  either  before  or  after,  how  the  various  advances 
in  skill  are  made.  In  learning  one  can  only  keep  trying 
and  be  alert  for  the  appearance  of  the  satisfactory 
movement  or  combination,  when  it  makes  its  appearance. 
This,  with  constant  striving  to  obtain  some  result  and 
to  repeat  the  result  when  obtained,  is  all  that  can  be  done 
toward  learning.  In  time  it  is  bound  to  be  successful. 
It  should  be  added  that  learning  must  be  spontaneous. 
Unless  the  movement  is  made  by  the  individual,  no 
learning  results.  Movements  forced  upon  an  animal 
or  man  by  a  trainer  or  by  electrical  stimulation  are  not 
learned.  To  be  learned,  movements  must  be  hit  upon 
in  the  course  of  intentional  effort.  There  is  no  short 
cut  to  learning. 

Control  of  Movement.  —  The  second  question  is  how 
movements  are  controlled  when  once  they  have  been 
learned,  —  why  one  movement  rather  than  another  is 
made  on  any  occasion.  It  follows  from  the  law  of  the 
connection  of  motor  and  sensory  nerves  that  control 
of  movement  must  always  be  primarily  control  of  idea 
or  control  of  sensation.  The  process  of  learning  is  to 
associate  movement  with  a  sensory  process ;  when  the 
connection  has  been  established,  the  movement  results 
whenever  the  related  idea  or  sensation  dominates  con- 
sciousness. The  immediate  antecedent  of  a  movement 
is  ordinarily  an  idea.  In  speech,  the  expression  follows 
upon  the  thought  of  the  words.  In  repetition  of  spoken 
words,  the  expression  comes  when  the  word  to  be  re- 
peated is  heard.  Similarly  in  writing  from  dictation, 


CONTROL   OF   MOVEMENTS  339 

as  one  hears  the  words  the  hand  traces  them  upon  the 
paper.  The  writing  may  go  on  fairly  accurately  when 
no  attention  is  given  to  the  words.  The  student  in  a 
lecture  may  take  notes  without  knowing  much  of  what 
he  is  writing,  while  thinking  of  the  next  foot-ball  game, 
or  of  other  extraneous  matter.  The  connection  between 
the  auditory  region  and  the  motor  region  serves  to  keep 
the  hand  writing  properly,  whether  all  attention  is  fixed 
upon  the  movement  or  not.  The  immediate  antecedent 
of  the  movement  is  always  some  idea,  but,  in  addition, 
two  other  groups  of  sensory  processes  must  cooperate 
in  the  control  of  the  movement.  These  are,  in  James's 
terms,  the  remote  sensations,  sensations  from  the  eye 
or  ear,  and  the  resident  sensations,  from  the  muscles 
and  other  parts  of  the  moving  member. 

Remote  Sensations.  —  As  one  writes,  the  pen  is  guided 
by  the  sight  of  the  movements  that  are  made.  If  the 
pen  wanders  from  the  line  one  sees  it  and  brings  it  back. 
With  the  eyes  closed  or  in  the  dark,  writing  is  very  un- 
certain. In  speech,  the  ear  takes  the  place  of  the  eye. 
The  voice  is  modulated  by  the  ear.  When  a  discordant 
sound  is  started  it  is  checked  and  the  vocal  mechanism 
adjusted  to  give  the  desired  quality.  The  deaf  speak  in 
monotonous,  badly  modulated  tones  because  they  cannot 
know  what  sounds  they  make  and  so  cannot  change 
them.  Children  born  deaf  are  dumb  because  they 
have  no  incentive  to  speak  and  no  means  of  appreciating 
the  sounds  they  make.  They  can  learn  only  when  they 
are  taught  to  control  the  movements  of  the  vocal  organs 
by  touch.  Education  of  the  deaf  in  the  art  of  speaking 
is  necessarily  a  slow  process.  They  must  be  taught  to 


340  THE   ESSENTIALS    OF   PSYCHOLOGY 

reproduce  the  movements  of  the  teacher's  mouth  and 
larynx  as  they  feel  them  with  their  fingers  or  see  them 
in  the  glass.  Otherwise  learning  follows  the  usual 
laws.  After  they  have  reproduced  the  movement  by 
chance  and  know  through  touch  that  they  have  made  it, 
the  idea  of  the  word,  however  it  may  be  presented,  will 
lead  to  the  reinstatement  of  the  movement.  Later  they 
substitute  the  sensations  that  come  from  the  moving 
muscles  for  the  tactual  sensations.  This  never  becomes 
as  adequate  as  the  control  that  is  exerted  by  the  ear  of 
the  normal  individual.  The  deaf  child  always  is  deficient 
in  intonation  and  modulation. 

Resident  Sensations.  —  In  addition  to  these  im- 
pressions from  the  higher  senses,  sensations  from  the 
moving  member  serve  to  control  all  movement.  The 
best  evidence  of  this  statement  is  the  fact  that  when 
the  kinaesthetic  sensations  are  lacking,  control  is  in- 
adequate. Tabetic  patients,  whose  Columns  of  Goll 
and  Burdach  in  the  spinal  cord  have  been  destroyed  by 
disease  and  who  in  consequence  have  no  sensations  from 
the  muscles,  may  tend  to  make  a  movement  and  have 
the  appropriate  idea,  but  the  movement  will  not  follow, 
or  will  be  weak,  or  entirely  misdirected.  A  child  whose 
sensory  nerves  in  the  organs  of  speech  have  not  developed 
will  not  learn  to  talk  unless  special  methods  are  devised, 
and  then  will  learn  slowly  and  imperfectly.  The  sen- 
sations from  the  muscles  and  the  moving  parts  are  con- 
stantly coming  in  to  exert  an  influence  upon  the  amount 
and  character  of  the  motor  discharge.  They  adjust  the 
movement  to  the  position  of  the  member  at  the  moment, 
and  exert  a  general  guidance  upon  the  movement. 


CONTROL   OF   MOVEMENTS  341 

The  Incentive  to  Action  Takes  Many  Forms.  —  Each 
of  these  directing  and  controlling  factors  may  be  explicit, 
or  it  may  be  implicit ;  it  may  be  conscious  or  uncon- 
scious, or  vaguely  conscious.  It  has  been  asserted  at 
different  times  that  the  initiating  idea  must  be  a  kinaes- 
thetic  memory  of  the  act,  that  it  must  be  a  picture  of 
the  member  in  a  certain  position,  and  that  it  may  be  any 
one  of  several  definite  ideas  or  images.  The  more  the 
antecedents  of  action  are  observed,  however,  the  more 
evident  it  becomes  that  the  directing  idea  may  be  any 
sort  of  image  whatever.  In  many  cases,  the  imagery  is 
very  indefinite,  seems  to  be  very  largely  lacking.  It 
may  be  a  mere  thought  that  it  is  desirable  to  do  a  certain 
thing ;  it  may  be  any  part  of  the  act  to  be  performed. 
In  other  cases,  one  may  make  up  one's  mind  to  do  a 
certain  thing  at  a  certain  time,  and  when  the  time  comes, 
it  is  done  with  no  appreciable  idea  whatever.  The 
expected  sensation  starts  the  movement  decided  upon 
without  any  idea  or  intention  intervening.  Thus,  at 
the  moment  you  read  these  lines,  we  may  imagine  that 
you  decide  to  underline  them.  You  may  think  of  the 
position  your  hand  should  take  to  bring  the  pencil  to 
the  proper  point  on  the  page,  and  you  may  think  of  this 
position  in  kinaesthetic  imagery  or  in  visual  imagery; 
again,  you  may  think  merely  in  words,  '  I'll  underline 
that,'  and  draw  the  line  with  no  further  imagery  what- 
ever. Again,  you  may  have  decided  at  the  beginning 
of  the  reading  that  you  will  underline  the  important 
passages,  and  now  think  nothing  more  than,  '  this  is 
important,'  and  the  movement  starts  at  once.  The 
general  rule  is  that  there  is  more  imagery  the  first  time 


342         THE  ESSENTIALS  OF  PSYCHOLOGY 

a  movement  is  made,  and  that  the  imagery  decreases 
in  amount  the  more  frequently  the  movement  is  repeated. 
In  general,  too,  each  part  of  the  movement  is  at  first 
preceded  by  a  separate  idea,  while,  after  several  repe- 
titions, all  that  is  necessary  is  to  think  of  some  part 
of  the  movement  or  of  something  that  makes  the  move- 
ment desirable,  and  it  is  executed  without  further  outlining 
of  the  details.  Such  a  general  thought  as, '  that  is  impor- 
tant,' is  the  usual  cue  for  the  more  familiar  movements. 
Controls  often  Automatic.  —  The  controlling  sen- 
sations, resident  and  remote,  act  even  less  consciously. 
As  one  underlines,  one  is  aware  through  the  eyes  of  the 
course  of  the  movement ;  one  sees  the  lines  grow,  but 
does  not  realise  that  these  visual  impressions  play  any 
important  part  in  the  control.  The  control  is  not  con- 
scious and  deliberate.  One  does  not  first  appreciate  the 
visual  sensations,  and  then  decide  in  terms  of  them  how 
the  pencil  must  move  to  make  the  line  straight.  One 
occasionally  notices  that  the  line  is  getting  crooked  and 
consciously  corrects  it ;  but,  if  all  goes  well,  the  only 
way  of  being  sure  that  sight  is  guiding  the  movement 
is  to  find  that  one  cannot  draw  a  straight  line  with  the 
eyes  closed.  The  influence  of  sight  is  effective,  not 
only  in  determining  the  direction  and  character  of  the 
movement,  but  also  in  determining  its  force  or  intensity. 
One  of  the  most  striking  instances  of  this  is  the  illusion 
of  the  pound  of  lead  and  the  pound  of  feathers.  A 
pound  of  feathers  seems  very  much  lighter  than  a  pound 
of  lead,  because  the  large  bulk  calls  out  a  strong  motor 
discharge  for  the  feathers,  and  the  small  bulk  of  the  lead, 
a  slight  motor  discharge.  In  consequence,  the  feathers 


CONTROL   OF   MOVEMENTS  343 

are  lifted  very  rapidly,  the  lead  very  slowly.  The 
weight  that  rises  more  rapidly  than  was  expected  seems 
light,  the  weight  that  rises  more  slowly  than  was  expected 
seems  heavy.  For  our  present  purpose,  the  important 
phase  of  the  experiment  is  to  show  that  the  motor  im- 
pulse is  controlled  in  amount  by  remote  sensations. 
Sensation  may  overcome  knowledge.  If  one  is  told  in 
advance  that  one  object  is  light,  the  other  heavy,  the 
illusion  persists  on  lifting.  Even  when  told  that  each 
weighs  exactly  a  pound,  the  large  mass  still  calls  out  the 
larger  impulse,  and  is  raised  the  more  rapidly.  Given 
only  the  intention  of  raising  the  weight,  the  motor 
impulse  is  determined  primarily  by  the  visual  appear- 
ance of  the  object  to  be  lifted ;  other  sources  of  knowl- 
edge will  be  disregarded. 

The  same  sort  of  control  by  vision  may  be  seen  in  many 
other  movements.  In  speaking,  one  unconsciously 
adjusts  the  loudness  of  the  tone  to  the  distance  of  the 
listener,  the  size  of  the  room,  etc.  In  making  a  golf 
stroke,  the  force  of  the  blow  is  guided  by  the  sight  of 
the  green,  together  with  the  unexpressed  estimate  of 
the  distance.  In  each  of  these  instances,  the  strength  of 
the  movement  is  closely  adapted  to  the  visual  impres- 
sions, and  the  only  requirement  for  the  adaptation  is 
that  the  weight  to  be  lifted  or  the  object  to  be  hit  be 
definitely  looked  at,  or  have  been  observed  just  before 
the  movement.  The  control  by  the  kinaesthetic  sen- 
sations, the  resident  sensations,  is  similarly  unconscious. 
One  never  thinks  of  them  unless  attention  is  especially 
directed  toward  them,  and  even  then  one  is  more  likely 
to  be  conscious  of  the  visual  interpretation,  to  think  of 


344        THE  ESSENTIALS  OF  PSYCHOLOGY 

the  motion  of  the  member  in  remembered  visual  images, 
than  in  terms  of  the  kinaesthetic  sensations  themselves. 
One  misses  them  when  they  are  destroyed  by  disease, 
but  does  not  appreciate  them  when  present.  Three 
elements,  then,  combine  in  the  initiation  and  guidance 
of  a  movement,  (i)  The  general  idea  or  intention  to 
move.  This  is  found  in  the  thought  of  the  movement 
or  of  the  end  to  be  attained.  (2)  The  remote  sensations 
from  eye  or  ear.  (3)  The  resident  sensations  from  the 
moving  member  itself.  These  resident  and  remote 
sensations  control  the  direction  and  force  of  the  move- 
ments. 

Not  All  Ideas  Produce  Movements.  —  If,  as  has  been 
said,  the  immediate  antecedent  of  a  movement  is  an  idea, 
the  question  naturally  arises  why  all  ideas  do  not  lead 
to  movement  or,  more  particularly,  how  it  is  possible 
that  one  may  think  of  a  movement  without  making  it. 
One  may  think  of  saying  something  and  not  say  it,  one 
frequently  thinks  intently  of  an  act  without  performing 
it.  This  problem  has  been  much  discussed  but  has 
received  no  very  definite  answer.  The  probability  is 
that  there  is  no  particular  process  that  comes  invariably 
to  set  off  the  movement  after  it  has  been  decided  upon, 
but  any  one  of  a  number  of  different  circumstances  may 
serve  as  the  final  determinant  of  the  movement.  Of 
these,  the  most  important  is  the  wider  setting  in  which 
the  idea  presents  itself.  If  everything  else  in  the  situ- 
ation favours  the  movement,  it  will  be  made ;  if  the  idea 
of  the  moment  is  altogether  out  of  harmony  with  the  act, 
it  will  not  be  put  into  execution.  Thus,  if  one  has  been 
waiting  for  the  summons  to  dine,  one  goes  immediately 


THE   INCENTIVE   TO  ACTION  345 

to  the  table  when  it  comes ;  if  the  summons  comes  in 
the  midst  of  writing  a  sentence,  the  movement  will  at 
first  be  thought  of  vaguely,  but  nothing  will  happen. 
Sometimes  a  contending  image  or  idea  may  interfere 
with  full  attention  to  the  movement  itself,  or  other  con- 
siderations may  make  the  act  undesirable  at  the  moment. 
When  these  disappear,  the  act  results.  It  is  probable, 
when  everything  seems  ready  for  the  movement  but  it 
is  not  made,  that  the  explanation  is  to  be  found  in  some 
inhibiting  process,  some  vaguely  conscious  consideration 
that  blocks  the  path. 

The  Release  of  the  Movement.  —  One  of  the  best 
places  to  study  the  play  of  these  forces  and  considera- 
tions is  in  getting  up  in  the  morning,  which  is  made 
much  of  by  Professor  James,  and  which,  for  its  difficulty, 
seems  to  have  universal  appeal.  When  the  alarm  goes 
off,  one  intends  to  get  up,  one  even  thinks  of  the  move- 
ments that  are  to  be  made  in  their  order,  but  nothing 
happens.  Sometimes  one  suddenly  recalls  the  task  that 
must  be  finished  early  in  the  morning.  That  gives  the 
required  impetus,  and  the  various  habitual  movements 
are  begun.  Often,  however,  one  thinks  of  nothing  new ; 
there  seems  no  particular  incentive  to  the  movements 
just  before  they  begin ,  one  finds  one's  self  dressing  and 
that  is  all  that  there  is  to  the  whole  matter.  In  such 
cases  it  is  probable  that  the  act  begins  when  some  in- 
hibiting or  blocking  idea  disappears  or  is  forgotten,  that 
the  movement  is  due  to  the  removal  of  a  check  rather 
than  to  the  appearance  of  a  new  force.  In  brief,  the 
movement  is  induced,  not  merely  by  the  idea  regarded 
as  the  motive,  but  by  the  entire  mental  context  at  the 


346  THE   ESSENTIALS    OF   PSYCHOLOGY 

moment,  by  a  large  number  of  elements  that  constitute 
the  situation  and  the  attitude  toward  the  situation. 
In  any  case  the  release  of  the  movement  does  not  follow 
upon  any  definitely  assignable  mental  content,  but  is 
i  he  outcome  of  a  whole  mass  of  considerations  that 
combine  to  make  the  act  desirable. 

Will  and  Choice.  —  The  rudiments  of  action  are,  then, 
comparatively  simple.  One  acquires  the  possibility  of 
moving  by  random  movements  that  give  a  certain  result, 
and  the  connection  between  the  idea  of  the  movement  and 
the  movement  itself  is  established  by  frequent  repetition. 
At  all  later  times,  the  movement  may  be  made  whenever 
the  idea  comes  to  consciousness.  The  more  complex 
problems  of  action  are  really  problems  in  the  control 
of  ideas.  What  one  ordinarily  calls  will  is  exerted 
primarily  in  the  control  of  the  course  of  thought,  and 
action  follows  when  the  proper  thought  presents  itself. 
The  most  striking  instance  of  voluntary  control  is  the 
decision  between  alternative  courses  of  action.  Fre- 
quently two  courses  present  themselves  which  seem 
equally  attractive  or  impelling.  Decision  in  these 
cases  is  made  by  selecting  one  of  the  two  possible  ideas, 
the  idea  of  the  result  of  one  course  of  action  or  of  the 
other.  This  may  lead  in  turn  to  the  thought  of  the 
movement  necessary  to  realize  that  end.  Always  what 
is  chosen  is  not  the  movement  as  such,  but  an  idea ; 
either  the  result,  or  the  thought  of  the  movement  domi- 
nates consciousness  at  the  moment  of  choice.  When 
either  completely  dominates  consciousness,  the  action 
results.  Control  of  action  offers  nothing  that  has  not 
been  earlier  discussed  in  connection  with  the  control 


WILL  AS   CHOICE  347 

of  ideas,  or  with  attention,  —  the  selection  of  sensations. 
The  importance  of  action,  however,  makes  it  desirable 
to  study  the  old  laws  in  the  new  application. 

The  Mechanism  of  Choice.  —  When  making  a  choice 
between  two  courses  of  action,  one  thinks  of  the  probable 
results  of  each  and  chooses  the  one  which  offers  the 
greater  probability  of  a  desirable  outcome.  If  after 
class  it  is  a  question  between  going  home  or  to  a  shop, 
you  do  not  think  of  the  movement  as  such,  but  you 
decide  that  it  is  necessary  to  finish  the  task  at  home  at 
once,  while  your  purchases  may  wait  until  later  in  the 
day.  When  this  decision  has  been  made,  the  necessary 
movements  are  begun  at  once.  The  same  holds  of  the 
more  complex  life  problems.  Choice  of  a  profession, 
where  there  is  opportunity  for  choice  in  the  matter  at 
all,  is  a  choice  of  ends.  The  advantages  and  disadvan- 
tages of  each  profession  are  weighed  and  compared  with 
the  difficulties  that  must  be  overcome  in  obtaining  a 
preparation  for  each.  When  a  balance  has  been  struck, 
it  finds  expression  in  some  phrase,  such  as,  '  this  will  be 
my  lifework ' ;  from  that  time  the  first  step  toward  the 
entrance  upon  the  profession  is  kept  in  mind,  ready  to 
be  translated  into  action  when  occasion  arises.  The 
idea,  and  the  idea  alone,  is  chosen  at  the  moment ; 
translation  into  action  may  be  delayed  for  years. 

The  Conditions  of  Choice.  —  If  we  turn  back  to  ask 
what  it  is  that  makes  one  line  of  action  attractive  and 
the  other  repulsive,  we  can  do  no  more  than  enumerate 
different  elements  in  heredity,  education,  or  present 
mood.  In  action  as  in  attention,  two  classes  are  to  be 
distinguished,  —  one  due  to  interest,  the  other  to  social 


348        THE  ESSENTIALS  OF  PSYCHOLOGY 

pressure.  The  one  is  said  to  be  in  accordance  with 
desire,  the  other  to  arise  from  duty.  Desires  grow  out 
of  hereditary  tendencies  and  experience,  and  change 
with  the  mood  and  attitude.  Duties,  on  the  other 
hand,  come  mostly  from  social  influences,  from  ideals, 
and  are  relatively  permanent.  The  actions  from  desire 
promise  immediate  satisfaction ;  actions  from  duty  are 
attractive  from  their  more  remote  results.  The  outcome 
of  the  line  of  action  decided  upon  always  seems  at  the 
moment  of  choice  to  promise  the  greatest  amount  of 
good,  immediate  or  remote.  The  only  difference  is 
that  the  preliminaries  are  in  the  one  case  irksome  or  even 
disagreeable,  while  in  the  other  they  are  pleasant  even 
though  the  final  outcome  be  not  so  pleasant.  The 
conditions  of  non-voluntary  attention  are  also  the 
conditions  of  desire;  the  conditions  of  voluntary  at- 
tention are  the  conditions  of  duty. 

Choice  Determined  by  Instinct  and  Experience.  — 
Concretely,  if  one  ask  why  last  night  one  continued  at 
a  game  instead  of  turning  to  work  at  the  accustomed 
hour,  the  answer  would  be  found  in  the  instinctive 
pleasure  in  the  game,  or  in  the  pleasure  of  the  society, 
or  in  the  excuse  derived  from  experience  that  the  fatigued 
condition  would  make  study  at  that  time  prejudicial  to 
good  work  on  the  morrow.  The  first  two  occasions  for 
the  decision  lead  back  to  heredity,  to  instinct,  while  the 
latter  is  an  expression  of  experience.  Suppose  that  the 
game  had  been  given  up  and  one  had  turned  to  work, 
the  explanation  would  be  found  in  social  pressure, 
in  the  dominance  of  ideal  or  remote  pleasures  over  the 
instinctive  and  experiential.  One  would  have  con- 


WILL   AS   CHOICE  349 

sidered  the  unpleasantness  of  confessing  ignorance  be- 
fore fellow-students,  or  one  would  have  had  in  mind  the 
desire  to  stand  well  at  the  end  of  the  college  course,  or 
would  have  considered  the  importance  of  that  lesson  for 
success  in  the  chosen  profession,  or,  still  more  remotely, 
one  may  have  developed  an  ideal  of  doing  well  every- 
thing that  is  required.  Even  this  last  ideal  probably 
has  a  social  origin,  although,  after  social  approval  has 
rewarded  action  in  harmony  with  that  ideal  or  punished 
departures  from  the  ideal  sufficiently  often,  action  in 
accordance  with  it  becomes  a  habit,  and  there  is  ordi- 
narily no  thought  at  the  moment  of  the  decision,  either 
of  the  ideal  or  the  consequences  of  the  action.  One 
turns  to  work  because  one  feels  that  one  must,  because 
one  feels  uncomfortable  if  the  game  is  not  given  up.  To 
perform  the  accepted  and  acknowledged  duty  is  essential 
to  immediate  comfort.  The  factors,  then,  that  determine 
choice  are,  on  the  one  hand,  the  instincts  of  the  indi- 
vidual, corrected  by  his  experience,  immediate  and 
remote ;  and,  on  the  other,  ideals  derived  from  society. 
Ultimately  the  social  factors  go  back  to  experience,  so 
that  one  may  assert  that  choice  is  the  outcome  of  instinct 
and  experience.  Conflict  of  desires  is  merely  conflict 
between  motives  developed  in  experience  or  heredity, 
each  of  which  tends  to  make  a  corresponding  course  of 
action  desirable. 

The  conflicts  most  important  and  most  emphasised 
are  those  between  instincts  and  instinctively  pleasant 
habits  on  the  one  hand,  and  ideals  on  the  other.  On 
the  whole,  it  seems  at  first  that  the  acts  favoured  by 
instinct  are  low  and  unworthy,  while  the  acts  imposed 


350        THE  ESSENTIALS  OF  PSYCHOLOGY 

by  society  and  ideals  are  high  and  moral.  The  oppo- 
sition is  only  apparent.  Some  of  the  acts  in  themselves 
noblest,  such  as  certain  forms  of  self-sacrifice,  are  in- 
stinctive, while  society  has  endeavoured  at  times  to 
enforce  altogether  unworthy  ideals.  The  apparent  con- 
flict arises  because  society  emphasises  acts  in  them- 
selves unpleasant  which  need  all  of  the  social  enforce- 
ment possible,  while  the  instincts,  good  and  bad  alike, 
are  strong  enough  to  take  care  of  themselves.  Society 
imposes  rules  where  instincts  are  insufficient,  or  have 
in  practice  proved  undesirable,  or  less  desirable  than  a 
method  of  conduct  that  has  grown  up  through  trial  and 
error  and  been  transmitted  from  generation  to  genera- 
tion by  tradition  and  social  institutions.  Where  instinct 
and  tradition  and  social  institutions  come  into  conflict, 
all  the  strength  of  public  sentiment  is  needed  to  enforce 
traditional  and  conventional  acts  against  instinct.  In 
consequence,  a  premium  is  put  upon  them  by  calling 
them  high  and  noble,  while  the  instincts  are  either 
considered  unworthy  or  are  taken  for  granted.  As  a 
matter  of  fact,  instincts  mark  out  only  the  rough  outlines 
of  conduct.  The  limits  to  instinct,  or  the  demarkation 
of  one  necessary  instinct  from  another,  is  not  given  in 
the  instinct,  but  must  be  learned  by  the  individual  or 
society.  We  have  egoistic  and  altruistic  instincts,  but 
there  is  nothing  in  instinct  to  show  how  far  one  should 
be  selfish,  and  how  far  sympathetic  on  particular  occa- 
sions. These  checks  and  balances  must  arise  through 
social  intercourse.  When  they  have  developed,  they  are 
just  as  important  for  the  survival  of  the  social  group 
as  are  the  instincts  themselves.  These  acts  enforced 


WILL  AS   CHOICE  351 

by  social  pressure  are  said  to  constitute  duties,  as  opposed 
to  desires  which  are  largely  instinctive.  Choice,  then, 
is  always  choice  of  a  result.  Often  one  finds  that 
choice  is  the  outcome  of  a  conflict  of  desires  with  duties, 
of  instincts  against  ideals.  At  other  times,  choice  is 
nothing  more  than  a.  weighing  of  the  alternative  methods 
of  attaining  an  end  that  is  approved  both  by  desire  and 
duty.  Decision  is  in  terms  of  past  experience.  The 
end  that  has  proved  most  successful  in  the  past  or  that 
promises  best  in  the  light  of  the  knowledge  of  the  agent 
will  be  chosen  and  will  result  in  action. 

Will  Identical  with  Conditions  of  Choice.  —  So  far 
we  have  not  made  use  of  the  word  '  will,'  although, 
in  popular  and  much  scientific  discussion,  will  is  the 
word  used  most  frequently  to  explain  action.  Will, 
as  Angell  says,  is  merely  a  word  to  designate  the  whole 
mind  active.  Will  may  be  defined  as  the  sum  of  the 
conditions  of  choice.  It  is  the  term  used  to  designate 
the  entire  original  disposition  of  the  individual,  to- 
gether with  its  modification  by  experience,  when  ap- 
plied to  action.  It  is  no  new  force  or  thing;  it  is  the 
application  to  the  control  of  action  of  all  the  influences 
that  control  attention,  perception,  and  the  course  of 
ideas.  Even  here,  these  forces  control  attention  and 
ideas  first,  and  control  action  only  as  they  control  atten- 
tion and  thought;  but  since  action  is  practically  the 
most  important  or  at  least  the  most  striking  psychological 
phenomenon,  the  term  '  will '  is  usually  reserved  for 
action.  Ordinarily  will  is  not  applied  to  all  of  these 
forces,  but  is  reserved  for  the  ideals  that  enforce  social 
traditions  and  laws.  When  one  acts  under  the  control 


352  THE   ESSENTIALS   OF   PSYCHOLOGY 

of  an  ideal  or  for  the  accomplishment  of  a  remote  end, 
one  is  ordinarily  said  to  have  performed  a  voluntary 
act ;  when  one  gives  way  to  a  desire  of  an  instinctive 
nature,  one  is  said  to  have  acted  on  impulse.  On  the 
other  hand,  one  is  said  to  have  acted  voluntarily,  if  the 
act  that  corresponds  to  the  ideal  has  been  deliberately 
weighed  against  the  desire,  and  the  ideal  has  won.  In 
general,  voluntary  acts  are  those  which  grow  out  of  a 
conflict  between  instincts  and  ideals,  in  which  ideals 
prevail. 

Will  as  Control  by  Ideals.  —  Again,  one  may  see  in 
the  application  of  the  terms  strong  and  weak  will  the 
tendency  to  identify  will  with  control  by  ideals.  A 
strong-willed  individual  is  one  who  works  tenaciously 
for  a  remote  good,  while  the  weak-willed  individual  is 
one  who  is  constantly  turned  aside  by  some  momentary 
desire.  Tenacity  in  holding  to  a  purpose  is  probably 
inherited ;  the  character  of  the  purpose  is  the  outcome 
of  training.  The  strong-willed  individual  may  be  good 
or  bad,  but  he  always  has  an  ideal  or  set  of  ideals,  and 
bends  all  of  his  acts  to  their  attainment;  while  the 
weak-willed  individual  is  controlled,  not  by  his  ideals, 
but  by  instincts  and  impulses  excited  by  the  changing 
factors  in  the  environment.  The  ideals  that  control  in 
the  strong-willed  man  are  developed  by  living  in  society ; 
they  are  very  largely  the  ideals  of  the  particular  com- 
munity or  family  in  which  the  individual  has  grown  up, 
modified  and  enlarged  by  the  wider  knowledge  of  the 
individual  obtained  hi  any  way  whatever.  You  can  see 
in  the  talk  of  the  young  boy  the  ideals  of  his  parents. 
Later  these  ideals  are  modified  by  the  school  influences ; 


TRAINING   WILL  353 

still  later  by  his  reading ;  and  then  by  the  chosen  .pro- 
fession. Now  and  again,  as  the  result  of  thinking,  an 
individual  decides  that  the  ideals  of  the  community  are 
wrong,  and  sets  up  for  himself  some  modification  of 
them ;  but  important  variations  of  this  sort  are  relatively 
rare,  and,  before  they  become  of  value,  must  be  tested 
and  accepted  by  the  wider  social  group.  In  general, 
the  ideals  of  the  individual  are  the  ideals  of  his  com- 
munity. 

Training  of  Will.  —  Training  will  is,  in  the  last  analysis, 
training  the  man.  Any  sort  of  learning  will  have  its  in- 
fluence upon  action.  The  more  one  knows,  the  better 
one  can  act,  and  training  for  action  cannot  be  separated 
from  training  of  any  other  kind.  Three  topics  may  be 
discussed  in  this  connection  as  having  particular  bearing 
upon  the  problem.  First,  we  may  say  that  choice  is  very 
frequently  a  matter  of  habit.  If  one  of  two  alternative 
lines  of  conduct  has  been  chosen  once,  that  decision,  if 
the  outcome  be  satisfactory,  will  make  the  same  choice 
probable  under  the  same  circumstances  in  the  future. 
In  the  adult  most  choices  are  of  this  habitual  kind  One 
no  longer  hesitates  between  work  and  exercise.  During 
the  period  habitually  devoted  to  work,  one  ordinarily 
declines  invitations  to  a  game;  when  invited  to  walk 
at  the  hour  for  exercise  one  accepts  just  as  immediately. 
One  declines  to  consider  investments  suggested  by  the 
canvasser  at  the  door,  or  coming  from  certain  firms 
which  have  been  sending  questionable  circulars.  In 
short,  most  of  the  decisions  of  to-day  were  settled  by 
decisions  of  the  same  kind  made  years  ago.  One  moral 
decision  strengthens  a  man  to  resist  similar  tempta- 


354        THE  ESSENTIALS  OF  PSYCHOLOGY 

tions  in  the  future,  and  a  large  number  of  decisions  of  the 
sort  makes  it  practically  impossible  for  him  to  decide 
in  the  wrong  way.  On  the  other  hand,  when  a  man 
decides  to  do  wrong,  he  makes  future  right  conduct  in 
that  respect  more  difficult,  and  each  immoral  act  makes 
the  reformation  more  unlikely. 

A  second  important  phase  of  training  will  is  in  develop- 
ing a  system  of  ideals.  This  can  be  done  only  indirectly. 
Ideals  come  unconsciously  from  the  society  in  which  the 
child  is  brought  up.  If  the  boy  finds  that  his  father  and 
older  brothers  constantly  disapprove  of  certain  acts  and 
approve  of  others,  he  takes  their  approval  for  law; 
their  ideals  become  his  ideals.  The  effective  moral 
ideals  come  from  the  approval  of  groups  and  classes. 
As  may  be  seen  in  any  community,  right  and  wrong  are 
made  by  public  sentiment,  not  by  law.  A  law  is  re- 
spected only  so  far  as  it  is  backed  by  public  senti- 
ment. This  holds  for  moral  laws  as  well  as  for  statu- 
tory enactments.  Development  of  ideals  is  largely 
through  social  approval  and  disapproval  of  the  acts 
and  expressions  of  the  child.  Proper  ideals  can  be 
developed  by  placing  the  child  in  the  proper  social 
atmosphere,  and  in  no  other  way.  This  atmosphere 
is  most  effective  when  it  comes  from  actual  contact 
with  people.  Books  and  reading  and  direct  exhorta- 
tion may  gradually  have  an  effect;  but  unless  you 
can  make  the  child  feel  that  the  class  to  whom  the 
ideals  belong  is  actually  his  class,  reading  and  precept 
are  of  little  value. 

A  third  difficulty  is  to  make  the  individual  act  up  to  the 
knowledge  and  ideals  that  he  possesses.  Every  once  in  a 


WILL  AS   HABIT  355 

while  one  observes  an  individual  who  knows  the  right 
and  approves,  but  does  wrong.  The  only  cure  for  this 
condition  is  to  develop  a  habit  of  action.  This  can  be 
done  most  certainly  by  making  the  child  appreciate 
the  advantages  of  action  and  the  disadvantages  of  in- 
action. An  individual  left  to  take  the  natural  conse- 
quences of  his  acts  will  soon  develop  a  habit  of  doing  the 
thing  that  he  sees  should  be  done,  at  the  time  that  it 
should  be  done.  It  is  only  the  individuals  who  are  pro- 
tected from  the  consequences  of  inaction  and  indecision 
who  continue  inactive  in  the  face  of  acknowledged  duties. 
If  a  habit  becomes  established,  there  is  no  longer  question 
whether  a  thing  shall  be  done  or  not;  the  situation  at 
once  evokes  a  decision,  and  the  decision  evokes  the  act. 
Training  will  consists  in  establishing  habits  and  in 
developing  ideals.  All  training  of  whatever  sort  is 
bound  to  develop  both  habits  and  ideals;  training  of 
will  cannot  be  distinguished  from  training  the  man  as 
a  whole. 

This  discussion  of  action  adds  but  one  essential  fact 
to  the  list  developed  in  the  earlier  chapters.  This  is  that 
a  movement  is  associated  with  some  sensory  process  and 
is  made  whenever  that  process  dominates  consciousness. 
The  movement  either  is  associated  with  the  idea  or 
sensation  at  birth  as  in  instinct,  or  becomes  associated 
with  it  through  the  process  of  chance  trial.  The  control 
of  action  is  primarily  control  of  ideas  or  of  sensations. 
Except  in  this  fact,  that  movement  follows  upon  idea, 
the  laws  of  action  are  the  laws  of  attention,  of  perception, 
and  of  reasoning. 


356  THE  ESSENTIALS   OF  PSYCHOLOGY 

QUESTIONS 

1.  Describe  the  characteristics  common  to  all  actions.     What 
are  the  forms  of  action  ?    What  serves  to  distinguish  them  ? 

2.  Enumerate  the  antecedents  of  a  voluntary  act.    Which 
can  be  regarded  as  the  real  cause  of  the  act  ?    Is  it  a  cause  or  an 
accompaniment  of  the  cause? 

3.  Do  you  ever  think  of  a  movement  without  making  it? 
What  prevents  the  act  ? 

4.  Can  you  control  a  reflex  act ?    How? 

5.  How  do  you  choose?    What  do  you  choose ?    What  makes 
you  desire  to  do  what  you  choose  to  do  ? 

6.  What  is 'will'? 

7.  Trace  out  the  instinctive,  experiential,  and  ideal  elements 
in  some  real  decision  you  have  made  during  the  day. 

EXERCISES 

1.  Try  to  develop  some  movement  that  is  latent.    Try,  for  ex- 
ample, to  wink  your  right  eye  without  closing  the  left.    Keep  a  rec- 
ord of  the  number  of  trials,  and  watch  the  spread  of  the  contraction 
from  a  neighbouring  muscle.     First  try  keeping  attention  fixed 
upon  the  eye  to  be  kept  open,  then  upon  the  eye  to  be  closed  while 
the  other  is  neglected.    Which  is  the  more  effective?    If  the 
movements  of  the  eyelids  have  already  been  dissociated,  try  patting 
your  chest  with  one  hand  while  you  rub  the  top  of  the  head  with 
the  other.    Keep  the  same  records. 

2.  Trace  the  process  of  acquiring  skill  with  the  cup  and  ball. 
Keep  a  record  of  the  proportion  of  successes  over  a  period  of  several 
days.    Trace  plateaus  and  the  occasions  for  the  sudden  rises.    If 
more  convenient,  any  other  simple  game  of  skill  may  be  substituted 
for  the  cup  and  ball. 

3.  Procure  two  objects  of  the  same  weight  but  of  unequal  size, 
and  try  to  train  yourself  to  lift  them  at  the  same  rate.     Can  you 
avoid  the  illusion  of  weight  or  rid  yourself  of  it  by  practice? 

4.  Try  writing,  while  with  hand  hidden  from  direct  observation 
you  watch  the  writing  in  a  mirror.    What  is  the  effect  ?  _  Which  of 


ACTION   AND   WILL  357 

the  three  contrpls  mentioned  in  the  text  is  disturbed  in  the  experi- 
ment ?     Can  you  overcome  the  difficulty  with  practice  ? 

5.  Study  yourself  while  making  a  high  dive.  If  several  at- 
tempts are  necessary  before  you  start,  try  to  trace  the  immediate 
antecedent  of  the  action.  If  diving  be  impracticable,  observe 
getting  up  on  a  cold  morning,  or  getting  into  a  cold  bath. 

REFERENCES 

JAMES  :  Principles  of  Psychology,  vol.  ii,  ch.  xxvi. 

ANGELL  :  Psychology,  chs.  xx,  xxi. 

THORNDIKE  :  Animal  Intelligence.    Psych.  Rev.  Mon.  Sup.,  vol.  2. 

BAIR  :  The  Development  of  Voluntary  Control.    Psych.  Rev.,  vol. 

8,  p.  474. 
PILLSBURY  :  Attention,  ch.  x. 


CHAPTER  XIV 
WORK,  FATIGUE,  AND  SLEEP 

FATIGUE  has  a  very  general  influence  upon  mental  and 
physical  efficiency.  It  modifies  behaviour  in  many  ways 
and  a  knowledge  of  its  laws  is  highly  important  for 
mental  hygiene.  Appreciation  of  the  great  value  of  an 
accurate  knowledge  of  the  most  profitable  periods  of 
work,  the  relation  of  the  quantity  and  quality  of  work 
to  its  duration,  and  the  general  effects  of  work  and 
rest  upon  health  and  well-being  have  furnished  the 
incentive  for  numerous  investigations  of  fatigue,  par- 
ticularly in  the  last  two  decades.  While  it  cannot  be  as- 
serted that  agreement  has  been  reached  upon  all  points, 
it  seems  worth  while  to  summarise  the  results  so  far 
obtained,  because  of  their  wide  application  to  the  activi- 
ties of  everyday  life.  It  is  desirable  to  know  what  the 
maximum  efficiency  of  the  individual  is  in  each  respect. 
It  is  desirable  to  work  up  to  the  limit  of  capacity,  in  emer- 
gencies at  least,  and  even  more  important  to  be  sure  that 
the  limit  is  not  overpassed. 

The  Nature  and  Signs  of  Fatigue.  —  The  first  question 
is,  what  is  fatigue  and  what  its  nervous  and  mental  mani- 
festations? In  general,  fatigue  may  be  defined  as  the 
decreased  capacity  for  work  that  comes  as  a  result  of 
work.  Mentally  it  is  usually  accompanied  by  sensa- 
358 


FATIGUE 


359 


tions  that  are  in  some  measure  an  index  of  the  degree 
of  fatigue.  Physiologically  it  has  been  demonstrated 
that  fatigue  is  accompanied  by  three  sorts  of  changes. 
First,  poisons  accumulate  in  the  blood  and  affect  the 
action  of  the  nervous  system,  as  may  be  shown  by  direct 
chemical  analysis.  Mosso  obtained  striking  results  by 
an  indirect  method  that  is  not  altogether  free  from  crit- 
icism. He  selected  two  dogs  as  nearly  alike  as  possible. 


FIG.  33.  —  Changes  in  the  nucleus  as  a  result  of  fatigue.  (A}  and  (B)  are 
both  from  the  spinal  ganglion  of  a  cat.  (.4)  shows  the  resting  condition, 
(B)  a  cell  after  electrical  stimulation  of  its  nerve  for  five  hours.  The  nuclei 
in  (B)  may  be  seen  to  be  much  smaller  and  to  be  very  irregular  in  outline. 
(From  'American  Text-book  of  Physiology,'  after  Hodge.) 

One  he  kept  tied  all  day,  the  other  he  exercised  until  by 
night  it  was  thoroughly  tired.  Then  he  transfused  the 
blood  of  the  tired  animal  into  the  veins  of  the  rested 
one  and  produced  in  him  all  the  signs  of  fatigue  that 
were  shown  by  the  other.  There  can  be  no  doubt 
that  the  waste  products  of  the  body  accumulate  in 
the  blood  and  interfere  with  the  action  of  the  nerve- 
cells  and  the  muscles.  It  is  probable  that  these  accu- 


360         THE  ESSENTIALS  OF  PSYCHOLOGY 

initiations  come  as  a  result  of  mental  as  well  as  of 
physical  work. 

A  second  change  in  fatigue  has  been  found  in  the  cell 
body  of  the  neurone.  Hodge  showed  that  the  size  of  the 
nucleus  of  the  cell  in  the  spinal  cord  of  a  bee  diminished 
nearly  75  per  cent  as  a  result  of  the  day's  activity,  and 
that  the  nucleus  became  much  less  solid.  A  third  change 
that  results  from  muscular  work  is  the  accumulation  of 
waste  products  in  the  muscle  tissue.  Fatigued  muscles 
contain  considerable  percentages  of  these  products. 
That  they  are  important  factors  is  shown  by  the  fact 
that  if  they  are  washed  out  of  the  fatigued  muscle  it 
regains  its  capacity  to  contract.  The  experiments  are 
performed  on  the  muscles  of  a  frog  that  have  been  cut 
from  the  body  and  fatigued  by  electrical  stimulation. 
When  they  will  no  longer  respond,  their  sensitivity  may 
be  renewed  by  washing  them  in  a  weak  salt  solution  to 
dissolve  the  products  of  fatigue.  It  is  probable  that 
these  products  stimulate  the  sense-organs  in  the  muscles 
and  thus  give  some  of  the  sensations  of  fatigue.  Of 
these  physical  effects  of  fatigue,  the  accumulation  of 
the  waste  products  in  the  blood  and  the  effects  upon  the 
nerve-cells  are  probably  common  both  to  mental  and 
physical  fatigue.  The  effect  upon  the  muscles  plays  a 
part  in  mental  fatigue  only  so  far  as  all  mental  work 
involves  some  musculai  activity. 

The  Analysis  of  Mental  Fatigue.  —  More  practical 
are  the  results  of  the  experiments  accumulating  in  recent 
years  upon  the  actual  course  of  the  work.  The  change 
in  capacity  in  the  course  of  work  has  been  shown  to  be 
dependent  upon  a  number  of  factors  that  may  be  isolated. 


MENTAL  FATIGUE  361 

First  we  have  fatigue,  the  decreased  capacity  for  work, 
which  may  be  assumed  to  increase  regularly  with  the 
amount  of  work  accomplished.  But  this  decrease  in 
capacity  is  partly  obscured  by  another  effect  of  work  just 
as  well  established,  the  resulting  practice.  Every  bit 
of  work  not  only  diminishes  capacity  but  also  gives 
increased  efficiency  for  the  same  sort  of  work.  These 
two  factors,  practice  and  fatigue,  may  be  regarded  as 
always  present  and  always  opposed.  The  result  is  that 
each  obscures  the  effects  of  the  other.  When  work  first 
starts,  practice  increases  more  rapidly  than  fatigue  and 
in  consequence  one  can  do  more  after  working  for  a 
little  time  than  was  possible  at  first.  The  course  of 
recovery  from  the  two  effects  is  very  different.  Re- 
covery from  fatigue  is  rapid.  It  is  ordinarily  entirely 
complete  after  a  night's  rest  and  begins  to  be  appre- 
ciable as  soon  as  a  task  is  finished.  On  the  other  hand 
the  effects  of  practice  persist  over  long  periods  of  time. 
Days  and  years  after,  some  of  its  influence  may  be 
noticed.  Two  other  factors  are  important  in  deter- 
mining the  course  of  the  practice  curve,  —  one  may  be 
called  mental  inertia,  the  other  the  incentive.  When 
one  first  starts  a  task,  work  is  difficult  and  slow ;  as  time 
goes  on,  work  gradually  increases  in  amount  and  ac- 
curacy. When  once  started,  work  proceeds  at  the  regular 
rate  and  stopping  may  be  difficult ;  or  more  truly,  it  is 
easier  to  continue  work  than  it  is  to  stop  and  begin  again. 
Then  one  may  distinguish  the  initial  and  final  incentive. 
One  works  very  much  harder  when  first  beginning  a  task 
than  later.  Toward  the  end  there  is  nearly  always  a 
final  spurt  that  again  increases  considerably  the  rate  of 


362        THE  ESSENTIALS  OF  PSYCHOLOGY 

work  and  the  amount  accomplished.  Finally,  as  one 
becomes  accustomed  to  the  conditions,  one  works  to 
better  advantage  than  when  first  beginning. 

The  Economical  Periods  of  Work.  —  The  most  eco- 
nomical period  of  work  is  that  in  which  one  gets  all  the 
advantages  of  continued  work  without  going  on  to  the 
point  of  fatigue.  It  is  of  course  impossible  to  give  any 
general  rules  that  will  apply  to  all  kinds  of  work  and  to  all 
people.  How  much  work  may  be  done  depends  upon  the 
nature  of  the  work  and  upon  the  strength  of  the  individ- 
ual. The  fact  that  one  does  more  after  working  for  a 
little  time  than  when  one  first  begins  holds  universally. 
How  long  one  should  continue  after  the  effects  of  fatigue 
are  greater  than  the  benefits  of  practice  depends  upon 
the  kind  of  work  and  the  practical  necessities  for  its 
completion.  Fatigue  itself  is  not  to  be  avoided,  for  the 
lesser  degrees  wear  off  in  a  short  time  and  are  entirely 
overcome  by  a  night's  sleep.  The  poor  work  that 
results  when  fatigue  is  too  great  makes  effort  unprofitable, 
and  the  after  effects  in  the  form  of  overwork  may  have 
such  serious  results  as  to  put  a  premium  upon  avoiding 
them  at  all  reasonable  cost. 

The  Evidence  of  Fatigue.  —  It  is  not  at  all  easy  to 
know  when  one  is  in  danger  of  permanent  injury  from 
work.  Fatigue  shows  itself  by  sensations  of  different 
sorts,  some  from  tired  muscles,  some  of  a  more  indefinite 
character  from  the  inner  organs.  These  sensations, 
however,  are  not  always  associated  with  fatigue  itself. 
Often  one  feels  tired  when  actual  trial  shows  no  marked 
incapacity  for  work.  Rather  it  is  usual  for  the  best 
work  to  be  done  when  the  sensations  indicate  a  state 


FATIGUE   AND   REST  363 

of  bodily  inefficiency  before  work  is  begun.  Even  the 
capacity  for  doing  work  is  not  an  invariable  sign,  because 
it  is  not  unusual  to  be  able  to  do  good  work  when  the 
organism  is  fatigued  to  the  point  where  continued  work 
will  do  injury  of  a  permanent  character.  One  must  be 
guided  by  taking  into  consideration  three  factors,  —  the 
sensations  of  fatigue,  the  quality  of  the  work,  and  what 
previous  experience  has  shown  to  be  the  probable  after 
effects.  It  is  usually  Inadvisable  to  persist  to  the  point 
where  a  night's  rest  will  not  remove  fatigue  and  restore 
the  original  capacity.  Certainly  long-continued  work 
beyond  this  stage  is  bound  to  have  serious  consequences. 

The  Best  Period  for  Rest.  —  To  know  how  long  to 
rest  between  periods  of  work  is  as  important  as  to  know 
when  to  stop.  Results  of  experiments  indicate  that  the 
length  of  the  rest  that  should  be  introduced  between 
the  periods  of  work  depends  upon  the  length  of  the  pre- 
vious work  and  upon  the  character  of  the  work.  The 
rest  should  be  long  enough  to  permit  recovery  from 
fatigue  but  not  to  lose  the  mental  momentum.  After 
long  periods  of  work,  two  hours  or  more,  the  most 
advantageous  intermission  is  approximately  fifteen 
minutes;  for  relatively  short  periods  five  minutes  has 
proved  itself  most  satisfactory.  Longer  periods  waste 
too  much  time  and  cause  a  loss  of  inertia  and  of  practice 
that  is  not  compensated  for  by  recovery  from  fatigue. 
Shorter  rests  merely  cause  loss  of  inertia  without  any 
compensating  rest. 

Change  of  Work  No  Rest.  —  Several  facts  that  have 
been  suggested  by  experiments  are  contrary  to  the  com- 
mon assumptions  of  many  people.  For  example,  it  is 


364        THE  ESSENTIALS  OF  PSYCHOLOGY 

believed  usually  that  one  may  rest  through  change  of 
work,  —  that  if  one  has  been  tired  by  mental  work  of 
one  sort  it  is  not  necessary  to  rest  altogether,  but  by 
changing  to  something  else  one  may  become  rested 
through  the  change.  The  one  important  investigation 
on  this  point  indicates  that  the  everyday  assumption  is 
not  in  harmony  with  the  facts.  An  hour's  work  learning 
nonsense  syllables  followed  by  a  half  hour's  practice  on 
mental  arithmetic,  with  a  return  to  the  nonsense  syllables, 
rests  one  no  more  than  a  continued  period  of  nonsense 
syllables.  This  is  on  the  assumption  that  learning  non- 
sense syllables  is  no  more  difficult  than  mental  arithmetic. 
If  one  turns  from  a  more  difficult  to  an  easier  task,  one 
will  of  course  not  be  so  tired  as  if  one  had  continued  with 
the  more  difficult.  So  far  as  these  results  can  be  ac- 
cepted, it  seems  that  all  sorts  of  mental  fatigue  are  of  the 
same  kind,  and  that  it  is  not  possible  to  rest  one  function 
while  exercising  another.  There  is  so. much  in  common 
between  the  different  mental  operations  that  all  become 
tired  together.  It  is  possible  that  the  commonly 
accepted  opinion  to  the  contrary  is  due  to  the  greater 
interest  one  may  have  in  a  new  task.  One  ordinarily 
turns  from  a  task  only  when  obstacles  have  presented 
themselves  or  when  for  some  reason  the  work  has  become 
uninteresting.  It  is  possible  that  the  greater  interest 
in  the  new  work  and  consequent  greater  effectiveness  are 
mistaken  for  recovery  from  fatigue. 

Mental  and  Physical  Fatigue  One.  —  Very  similar  is 
the  attitude  toward  the  problem  of  the  relation  between 
mental  and  physical  fatigue.  It  is  generally  believed 
that  one  may  rest  from  mental  work  while  exercising, 


MENTAL  AND   PHYSICAL  FATIGUE  365 

but  experiments  indicate  that  capacity  for  mental  work  is 
decreased  by  physical  work  if  it  is  too  difficult.  If  one 
takes  a  vigorous  run  or  other  severe  exercise  between 
two  periods  of  the  same  sort  of  work,  as  in  the  experi- 
ments mentioned  above,  the  capacity  for  mental  work 
is  diminished  rather  than  increased.  Here  as  before  the 
effect  will  depend  upon  the  severity  of  the  task.  If  the 
exercise  be  mild,  one  will  rest  relatively  just  as  one  does 
during  less  difficult  mental  work.  In  fact,  the  whole 
question  of  work  and  fatigue  is  relative,  as  one  never 
rests  absolutely  except  during  sleep,  and  even  then  there 
is  merely  gain  of  repair  over  waste,  not  absolute  quies- 
cence of  all  functions.  The  identity  of  mental  and 
physical  fatigue  has  been  demonstrated  many  times, 
both  that  mental  work  induces  physical  fatigue  and  that 
physical  work  induces  mental  fatigue.  One  cannot  do 
severe  mental  work  effectively  after  a  hard  day  of  phys- 
ical labour,  and  experiments  show  that  one  is  less  ca- 
pable of  physical  after  hard  mental  work.  This  general 
identity  of  mental  and  physical  work  and  fatigue  is  being 
recognised  by  the  physician.  A  patient  suffering  from 
overwork  as  a  result  of  too  much  study  or  worry  is  no 
longer  advised  to  take  much  exercise,  but  is  put  to  bed 
or  given  very  little  easy  exercise.  Of  course  this  does 
not  imply  that  exercise  is  not  beneficial  in  health. 
Exercise  is  essential  to  the  development  and  health  of  the 
body,  and  needs  no  justification.  One  should  not  expect 
to  be  able  to  work  immediately  after  exercise,  but  in  the 
long  run  its  effects  are  beneficial. 

Morning  and  Evening  Workers.  —  Another  interesting 
result  of  recent  investigations  is  that  there  are  daily 


366        THE  ESSENTIALS  OF  PSYCHOLOGY 

rhythms  of  capacity  for  work,  —  that  every  one  has  a  cer- 
tain part  of  the  day  during  which  he  has  greater  capacity. 
According  to  one  authority,  men  divide  naturally  into 
morning  and  evening  workers.  The  one  group  is  at 
its  best  early  in  the  morning ;  the  other  group  does  not 
reach  its  full  capacity  until  toward  evening,  —  the 
amount  and  accuracy  of  the  work  increases  steadily 
through  the  day.  It  has  not  been  determined  whether 
the  difference  is  innate  or  the  result  of  habit,  but  in  an 
adult  accustomed  to  mental  work  one  habit  or  the  other 
is  always  readily  demonstrated,  even  if  the  individual 
himself  is  unaware  of  it.  Evidently  one  should  take 
advantage  of  the  daily  rhythm  by  devoting  the  best  part 
of  the  day  to  the  more  difficult  tasks. 

Interest  Reduces  Fatigue.  —  It  should  be  added  that 
the  measurements  of  fatigue  upon  which  these  statements 
rest  are  derived  from  ordinary  routine  work  under  no 
particular  incentive  other  than  to  do  one's  best.  It  is 
certain  that  a  sufficiently  strong  desire  would  at  any 
stage  have  brought  the  rate  of  work  back  to  the  maxi- 
mum, at  least  for  a  little  time.  Even  in  muscular  work 
fatigue  comes  more  slowly  if  the  worker  has  an  incentive 
and  the  work  is  interesting.  Phenomena  of  this  kind 
have  led  some  writers  to  argue  that  fatigue  is  an  illusion. 
That  what  is  called  fatigue  is  really  ennui  or  boredom. 
This  conclusion  overlooks  the  very  evident  after  effects 
of  severe  prolonged  work  in  decreased  efficiency  over 
considerable  periods  and  even  in  diseased  nervous 
conditions.  While  the  amount  of  work  that  will  be 
accomplished  depends  very  largely  upon  the  incentive, 
it  does  not  follow  that  fatigue  is  not  real  and  a  factor  to 


FATIGUE  367 

be  considered  in  the  arrangement  of  the  day's  routine. 
The  statements  made  hold  for  the  course  of  ordinary 
work  where  the  incentive  is  constant  and  not  particularly 
strong.  If  the  incentive  is  increased,  the  absolute  times 
given  are  all  increased,  but  the  relative  values  remain 
approximately  the  same.  There  still  comes  a  time  when 
the  amount  and  accuracy  of  the  work  is  reduced  to  a 
point  where  work  does  not  pay.  In  some  degree,  too, 
the  after  effects  of  the  work  increase  with  the  amount  of 
work,  although  probably  not  in  the  exact  ratio  of 
accomplishment.  Work  done  willingly  and  cheerfully 
under  suitable  incentives  is  apparently  less  fatiguing  in 
the  long  run  than  a  smaller  amount  accomplished  under 
unfavourable  conditions.  One  may  even  agree  with 
James  that  in  moments  of  exaltation  one  may  perform 
at  a  rate  far  above  the  ordinary  level  without  permanent 
injury,  and  at  the  same  time  accept  the  results  of 
experiments  under  ordinary  conditions  as  a  guide  for 
daily  life. 

Fatigue  Inevitable  and  in  Moderation,  Desirable.  — 
The  discussion  of  fatigue  and  the  methods  of  obviating 
it  is  likely  to  leave  the  impression  that  fatigue  is  some- 
thing to  be  avoided  at  all  hazard.  This  is  far  from  being 
the  case.  Fatigue  is  unavoidable  if  one  works,  and  work 
is  essential  to  all  development.  As  was  said  in  the 
beginning,  work  has  two  effects,  fatigue  and  practice. 
Practice  remains  and  furnishes  the  endowment  of  the 
individual  for  all  later  work ;  fatigue  disappears  after  a 
night.  The  ordinary  net  effect  of  work  the  day  after  is 
an  increase  in  capacity.  The  general  effects  of  work  are 
altogether  desirable.  Fatigue  is  not  something  to  be 


368 


THE  ESSENTIALS  OF  PSYCHOLOGY 


avoided.  The  most  that  is  desirable  is  to  consider  the 
laws  of  fatigue  and  learn  to  work  to  the  best  advantage. 
The  aim  of  life  is  not  to  avoid  fatigue  but  to  accomplish 
as  much  as  possible  with  the  minimum  of  fatigue.  Fa- 
tigue is  undesirable  only  when  it  threatens  permanent 
injury,  rather  than  when  it  temporarily  reduces  capacity. 
Sleep.  —  Very  closely  connected  with  fatigue  in  prac- 
tice and  theory  is  sleep.  While  sleep  is  one  of  the  most 
common  phenomena  of  life,  it  is  also  one  of  the  least 
understood.  What  sleep  is  or  why  it  comes  on  is  as 
yet  not  a  matter  of  agreement.  Something  more  is 
known  of  the  course  of  sleep  and  we  may  begin  our 
discussion  with  that.  Several  experimenters  have 
measured  the  depth  of  sleep  at  different  times  during  its 


STRENGTH  OF  STIMULUS 

| 

1 

\ 

\ 

-^ 

HOURS  0,5     10     15    ZO     Z.S   3.0    3.5     4.0   45    5.0    5.5    B.O    6£    7.0    7-5  7.8 

FIG.  34.  —  Curve  showing  the  depth  of  sleep  at  different  periods  after  going 

to  sleep.     The  figures  on  the  horizontal  line  show  the  time  since  going  to 

sleep;  those  on  the  vertical  line  the  relative  heights  balls  must  be  dropped 

to  waken  the  sleeper.     (From  Howell :  '  Physiology,'  after  Kohlschiitter.) 


SLEEP  369 

course  by  determining  the  intensity  of  stimulus  required 
to  waken  an  individual.  They  all  agree  that  sleep  in- 
creases in  depth  rapidly  during  the  first  three-quarters  of 
an  hour  and  then  decreases  gradually  during  the  re- 
mainder of  the  night.  It  has  been  suggested  that  the 
recuperative  processes  predominate  in  the  latter  part  of 
the  period,  when  sleep  has  passed  its  climax.  Why  one 
goes  to  sleep  is  not  so  easily  answered.  Obviously 
sleep  has  some  relation  to  fatigue,  but  over-fatigue  is 
inimical  to  sleep.  One  ordinarily  goes  to  sleep  most 
readily  under  monotonous  stimulation ;  but  a  persistent 
idea,  if  more  exciting,  makes  sleep  impossible,  when  all 
else  is  favourable.  Opinion  at  present  inclines  to  the 
view  that  sleep  is  an  instinct,  a  form  of  reaction  of  the 
nervous  system  induced  by  certain  definite  stimuli,  and 
that  it  tends  also  to  recur  somewhat  rhythmically.  This 
response  is  favoured  by  withdrawal  of  external  stimuli, 
by  quiet  and  darkness,  by  a  moderate  degree  of  fatigue, 
by  relaxed  or  dispersed  attention,  and  ordinarily  through 
habit  is  more  easily  induced  at  a  particular  hour.  No 
one  of  these  conditions  alone  will  induce  the  condition 
or  response,  but  all  together  usually  suffice.  Like  many 
another  reaction  it  is  favoured  by  suggestion  or  expecta- 
tion. If  one  fears  one  is  to  have  a  bad  night,  sleep  is 
usually  slow  in  coming;  while  if  one  expects  restful 
sleep,  it  comes  promptly. 

The  Physiology  of  Sleep.  —  What  the  reaction  is  that 
causes  sleep  is  also  much  in  dispute.  Changes  have  been 
demonstrated  in  the  circulation.  Blood  pressure  is 
low  in  sleep  and  varies  inversely  with  the  depth  of  sleep, 
—  is  lowest  when  the  depth  of  sleep  is  greatest.  The 

2B 


370  THE   ESSENTIALS   OF   PSYCHOLOGY 

blood-vessels  in  the  brain  are  relaxed,  although  filled  with 
blood,  and  constrict  when  sleep  is  disturbed  or  during 
dreams.  Respiration  is  changed  in  characteristic  ways, 
and  all  of  the  vital  processes  have  their  activity  reduced. 
Some  change  certainly  occurs  in  the  nervous  system, 
also,  but  what  its  exact  character  is,  has  not  been  decided. 
Evidence  is  tending  toward  the  assumption  that  there 
is  some  loosening  of  the  connections  between  the  different 
elements,  such  as  increased  resistance  at  the  synapses  to 
the  passage  of  excitations,  but  how  it  is  brought  about  is 
still  entirely  conjectural.  Certain  it  is  that  the  nervous 
system  is  less  easily  aroused  during  sleep  and  that  the 
course  of  action  is  less  controlled.  Nervous  action  is  not 
abolished,  however,  as  is  proved  by  the  presence  of 
reflexes  and  by  dreams.  Whether  this  reduced  activity 
is  due  to  the  changes  in  circulation,  or  the  changes  in 
circulation  are  due  to  the  reduced  nervous  activity,  or 
each  is  a  result  of  some  common  cause,  cannot  be  decided 
from  the  facts  at  hand.  Whatever  sleep  may  be,  it  is 
obvious  that  it  is  a  state  which  conduces  to  the  restoration 
of  the  tissues  that  have  been  subjected  to  the  wear  and 
tear  of  the  day.  The  effects  of  fatigue  are  nullified ; 
the  cell  bodies  are  restored  to  their  normal  condition ; 
the  waste  products  are  eliminated  from  muscle  and  blood. 
On  the  whole,  sleep  seems  to  be  an  instinctive  or  habitual 
response  that  comes  at  a  more  or  less  regular  time,  that 
is  favoured  by  a  mild  fatigue,  and  by  the  absence  of 
external  disturbance.  During  the  period  of  sleep  the 
vital  processes  are  reduced,  the  higher  nerve-centres 
are  only  slightly  active,  and  the  processes  of  repair 
exceed  those  of  wear. 


SLEEP   AND   DREAMS  371 

Dreams.  —  Dreams  were  among  the  first  phenomena 
to  direct  attention  to  the  mental  life  and  have  always 
been  an  object  of  interest  to  the  popular  mind.  For 
psychology  they  emphasise  the  erratic  course  of  mental 
states  when  little  controlled.  Fundamentally  they  are 
an  expression  of  the  same  laws  as  the  processes  of  wak- 
ing life.  At  times,  they  are  initiated  by  external 
stimulation ;  at  other  times  one  can  trace  the  influence 
of  striking  events  of  the  preceding  day.  Thus,  cold  feet 
may  induce  a  dream  of  walking  barefoot  through  snow ; 
a  dog  shaking  the  bed  may  start  a  dream  of  a  storm  at 
sea.  The  images  which  persist  from  the  preceding  day 
are  said  by  Freud  to  be  the  point  of  origin  for  all  dreams. 
Both  sensory  stimuli  and  these  persisting  impressions 
are  ordinarily  much  transformed.  '  A  woman  who 
has  been  carving  a  duck  at  dinner  dreams  of  cutting 
off  a  duck's  leg,  but  seems  to  realise  that  it  is  her 
husband's  head  she  is  hacking  at.'  These  transfor- 
mations are  usually  brought  about  by  associations, 
sometimes  verbal,  more  frequently  through  events  that 
have  been  connected  in  time  or  place.  Thus  a  lady 
who  had  admired  a  baby  and  bought  a  big  fish  for 
dinner  dreams  at  night  of  finding  a  fully  developed 
baby  sewed  up  in  a  large  codfish.1  More  frequently 
the  elements  added  by  association  are  derived  from 
earlier  years,  sometimes  they  can  be  traced  to  definite 
early  experiences. 

The  constructions  are  usually  bizarre,  since  the  asso- 
ciations follow  lines  of  least  resistance  with  little  of 
the  restraint  from  context  and  wider  experiences  so 

* Havelock  Ellis :    ' The  World  of  Dreams,'  p.  37. 


372        THE  ESSENTIALS  OF  PSYCHOLOGY 

prominent  in  the  waking  life.  The  recognition  and  belief 
processes  are  also  impaired  and  one  recognises  objects 
entirely  unfamiliar  and  accepts  as  true  statements  and 
constructions  manifestly  absurd  when  tested  by  the 
usual  standards.  This  lack  of  control  and  uncritical 
attitude  may  both  be  explained  from  the  fact  that  large 
portions  of  the  cortex  are  asleep  and  the  small  remainder 
must  both  control  and  censor  the  mental  constructions. 
One's  emotions  and  moral  standards  too  are  often  com- 
pletely transformed,  probably  also  an  expression  of  the 
reduction  in  the  number  of  experiences  that  pass  upon 
the  processes.  The  peculiarities  of  dreams  may  be  in 
part  due  to  the  great  condensation  frequently  present. 
The  events  are  merely  referred  to,  and  then  when  the 
dream  is  recalled  the  references  are  expanded.  It  is 
this  that  makes  possible  dreaming  of  a  number  of 
occurrences  in  a  very  short  interval.  Lack  of  space 
makes  it  necessary  to  omit  any  elaborate  discussion  of 
recently  developed  theories  of  dreams  which  expand 
these  points.  We  must  content  ourselves  with  the 
statement  that  they  are  expressions  of  the  ordinary 
laws  of  mental  processes,  often  much  exaggerated  owing 
to  the  weakening  of  the  directing  agencies. 

QUESTIONS 

1.  Define  fatigue. 

2.  How  can  you  tell  when  you  are  tired  mentally? 

3.  Describe  the  ordinary  course  of  work.    How  would  rate  and 
accuracy  vary  if  you  worked  hard  for  a  two-hour  period  ? 

4.  Can  you  rest  by  changing  work? 

5.  Is  physical  exercise  rest  for  the  mental  worker?    Is  it 
desirable? 


WORK,   FATIGUE,    AND   SLEEP  373 

6.  Formulate  for  yourself  a  program  of  work  for  a  typical  day 
based  on  the  statements  of  the  chapter. 

7.  What  is  sleep  ?    Is  going  to  sleep  a  passive  or  active  process  ? 

8.  What  physiological  changes  occur  in  sleep? 

9.  Recall  a  recent  vivid  dream.    Trace  the  different  incidents 
of  the  dream  to  physical  stimuli  and  to  memories,  if  you  can. 

REFERENCES 

MAX  OFFNER  :  Mental  Fatigue.    Tr.  by  Whipple. 

MYERS  :  Experimental  Psychology,  pp.  189-200. 

JUDD:  Psychology,  ch.  xiv. 

JONES  :  Freud's  Theory  of  Dreams,  Am.  Jour,  of  Psy.,  1910,  p.  283. 

SHEPARD  :  The  Circulation  and  Sleep. 


CHAPTER  XV 
THE  INTERRELATIONS  OF  MENTAL  FUNCTION 

Criticism  of  Faculty  Psychology.  —  For  the  sake  of 
convenience  we  have  been  treating  the  mental  operations 
separately  and  may  have  left  the  impression  that  each 
of  the  names  used  stands  for  a  separate  function  or  thing. 
This  was  in  some  degree  the  assumption  of  the  older 
psychologies  and  still  is  the  prevailing  popular  belief. 
One  speaks  of  attention  and  of  memory  and  of  other 
processes  because  they  represent  mental  capacities  which 
it  is  desirable  to  discuss  together.  The  popular  mind 
always  finds  it  easy  to  make  a  substance  of  the  function 
and  to  speak  of  the  memory,  the  will,  and  so  on,  as  if 
they  were  separate  entities  or  forces.  In  the  very  early 
psychologies,  these  functions  were  personified  and  the 
older  men  were  inclined  to  speak  as  if  mind  were  a 
partnership  in  which  each  partner  had  separate  abilities 
and  capacities,  and  as  if  these  capacities  were  practically 
independent  one  of  the  other.  In  the  discussions  of 
modern  psychology  there  is  no  such  implication.  The 
words  stand  for  nothing  but  observed  facts,  —  the  fact 
that  one  remembers,  that  one  acts  and  makes  decisions, 
or  that  one  attends.  What  may  be  behind  the  activity 
we  do  not  pretend  to  know,  but  we  certainly  do  not  care 
to  assert  that  any  '  thing  '  is  behind  any  act  or  activity. 

374 


THE  PRIMARY  MENTAL   FUNCTIONS  375 

The  Transfer  of  Training.  —  One  problem  of  con- 
siderable practical  importance  is  the  degree  of  relation 
and  the  mutual  dependence  of  the  different  capacities. 
In  connection  with  training  it  is  interesting  to  know  if 
one  may  train  a  capacity  by  training  some  other  ca- 
pacity, or  how  far  training  in  one  field  may  be  helpful 
in  some  other.  The  theoretical  considerations  may 
give  any  conclusion  indifferently,  and  popular  opinion 
seems  to  be  much  divided  as  to  how  far  the  effects  of 
training  may  spread  from  the  function  actually  exercised 
to  other  related  functions.  There  is  also  equal  differ- 
ence of  opinion  as  to  what  are  related  functions  and  how 
they  may  be  trained.  Two  opposing  general  principles 
are  currently  accepted  and  serve  as  a  basis  for  popular 
opinion.  On  the  one  hand,  the  separate  functions  have 
been  regarded  as  absolutely  distinct ;  on  the  other,  any 
training  is  assumed  to  be  effective  for  all  mental  ca- 
pacities. Obviously  with  such  wide  diversity  in  gen- 
eral theory,  there  is  a  necessity  for  appeal  to  closer 
analysis  and,  if  possible,  to  actual  trial. 

The  Primary  Functions  of  Mind.  —  Our  earlier 
analysis  has  shown  that  the  different  functions  have 
much  in  common.  The  fact  that  impressions  are  re- 
tained is  fundamental,  not  for  an  explanation  of  mem- 
ory only,  but  for  the  control  of  attention  and  action 
and  almost  everything  else.  It  must  give  the  materials 
of  reasoning  as  well  as  much  of  the  control  of  the  reason- 
ing operations.  A  complete  analysis  shows  that  we 
have  three  simple  processes  which  are  fundamental  for 
all  the  cognitive  operations,  and  for  many  of  the  feeling 
and  active  processes.  These  are  the  facts  of  sensation, 


376        THE  ESSENTIALS  OF  PSYCHOLOGY 

of  retention  and  recall,  and  of  selection  and  control. 
These,  together  with  the  complementary  processes  of 
recognition,  belief,  instinct,  and  feeling,  suffice  to  explain 
all  the  functions  of  consciousness.  Perception  depends 
upon  the  control  of  the  entering  sensation  plus  the  recall 
of  related  and  interpreting  elements  which,  in  their  turn, 
are  selected  to  harmonise  with  the  general  setting,  objec- 
tive and  subjective.  For  example,  one  comes  into  a 
furnished  room  tired  and  accordingly  a  chair  catches 
the  attention.  This  perception  involves  a  rhomboid 
of  colour  upon  the  retina;  earlier  experiences  replace 
the  rhomboid  with  a  square  surface,  acute  and  obtuse 
angles  by  right  angles,  and  so  on.  We  have  a  combina- 
tion of  sensations  and  memories,  controlled  by  the  needs 
of  the  moment,  a  process  we  call  perception.  Similarly 
one  comes  into  a  bare  room,  feels  tired,  and  the  sensa- 
tions with  the  general  setting  call  out  the  memory  of  a 
chair,  perhaps  of  the  same  chair.  We  call  this  process 
memory  or  imagination  according  as  the  recalled  chair 
is  familiar  or  unfamiliar.  The  only  appreciable  differ- 
ence in  the  two  processes  is  the  presence  in  perception 
of  the  rhomboid  of  colour  upon  the  retina.  Again  the 
memory  of  the  chair  may  start  a  tram  of  movements 
that  sends  one  into  the  next  room  for  a  chair  or  to  the 
telephone  to  order  one  seen  in  a  shop  window  an  hour 
before.  We  call  this  will,  but  it  is  different  from  mem- 
ory only  in  that  the  associated  movements  are  per- 
mitted to  run  then-  course,  —  again  under  the  control 
of  the  purpose  and  knowledge  of  one's  credit  at  the 
shop  and  the  permanence  of  the  need.  This  difference 
is  even  less  when  one  considers  that  every  memory  and 


THE   PRIMARY  MENTAL   FUNCTIONS  377 

every  perception  tends  to  call  out  movements  of  some 
sort,  and  that  what  really  distinguishes  them  from  will 
is  the  degree  or  amount  of  the  movement,  not  its  pres- 
ence or  absence.  In  memory  or  perception  the  motor 
discharge  ends  in  slight  movements,  while  in  will  the 
movements  are  an  important  part.  Any  of  the  other 
functions  ordinarily  given  distinct  names  may  be  re- 
garded as  differently  compounded  out  of  the  same  ele- 
ments. The  combinations  alone  are  different;  the 
elements  and  the  conditions  that  control  the  selection 
are  largely  the  same  in  each.  It  is  to  be  expected  that 
any  change  in  any  function  will  affect  in  some  degree 
each  of  the  other  functions.  Either  it  will  supply  new 
materials  that  may  enter  into  other  functions,  or  will 
change  the  conditions  that  control  the  selection  and 
arrangement  of  the  materials. 

Names  of  Processes  Are  of  Functions  not  Entities.  — 
Not  alone  are  the  different  functions  interrelated  as 
different  expressions  or  combinations  of  the  same  mental 
materials  and  laws,  but  in  any  single  act  each  is  likely 
to  be  involved  in  some  degree.  One  turns  in  quick  suc- 
cession from  memory  to  action,  from  reasoning  to  imagi- 
nation, and  then  to  perception,  and  each  is  distinguish- 
able from  the  others  only  by  abstract  analysis.  The 
separate  functions  are  really  not  more  separated  than 
are  different  applications  or  uses  of  the  same  function. 
The  memory  employed  in  learning  nonsense  syllables 
is  more  different  from  that  used  in  learning  historical 
events  in  their  logical  succession  than  is  the  latter  from 
the  reasoning  employed  in  reconstructing  some  partly 
forgotten  event  on  the  basis  of  its  remembered  antece- 


378        THE  ESSENTIALS  OF  PSYCHOLOGY 

dents.  The  first  two  are  certainly  memory,  the  latter 
is  just  as  certainly  reason.  What  is  different  and  what 
marks  the  lines  of  division  in  consciousness  are  the  uses 
to  which  certain  processes  are  put.  These  processes 
receive  names  that  correspond  to  the  uses,  even  when 
the  elements  or  conditions  are  essentially  the  same. 
The  problem  of  how  far  training  may  spread  must  be 
attacked  by  experiment  and  observation.  Nothing  in 
the  nature  of  mental  capacities  gives  certainty  that 
training  may  not  spread  from  one  function  to  another, 
and  nothing  indicates  that  training  in  one  field  has  any 
particular  amount  of  influence  in  any  other.  All  that 
can  be  said  on  general  principles  is  that  where  two  func- 
tions have  something  in  common,  training  in  one  will 
probably  have  an  effect  upon  the  other ;  where  there 
is  nothing  in  common,  training  in  one  capacity  will  be 
without  influence  upon  the  other.  On  purely  theoretical 
grounds  one  would  expect  that  use  anywhere  either  would 
provide  new  materials  or  would  add  new  elements  of 
control  that  might  be  used  in  any  other  field.  It  is 
altogether  probable  that  the  effect  of  many  activities 
upon  other  capacities  may  be  negligible  in  amount,  and 
so  of  no  practical  importance.  All  that  can  be  said 
with  any  certainty  is  that  one  may  expect  any  training 
whatever  to  spread  beyond  the  particular  function 
exercised  to  any  other  function  that  has  anything  in 
common  with  it.  The  problem  is  to  determine  what 
functions  have  enough  in  common  to  make  the  spread 
from  one  to  the  other  appreciable,  and  to  discover  means 
of  measuring  the  practice  and  its  effects  on  the  other 
functions.  Not  only  is  it  true  that  two  functions  of 


TRANSFER   OF   TRAINING  379 

different  names  have  much  in  common,  but  also  activi- 
ties that  ordinarily  are  grouped  under  the  same  name 
need  not  be  sufficiently  alike  to  make  training  in  one 
have  any  influence  upon  the  other.  For  example,  in 
memory  it  has  long  been  a  question  whether  training 
in  learning  things  of  one  sort  increases  the  capacity  for 
learning  things  of  another.  The  practical  problems  in- 
volved are  twofold,  —  first,  how  far  is  practice  in  a 
function  effective  in  increasing  the  capacity  for  exer- 
cising the  same  function  on  other  material ;  and  second, 
how  far  will  training  in  one  have  an  effect  upon  other 
functions  and  capacities. 

Can  Memory  Be  Trained  ?  —  For  an  answer  to  our 
question  we  must  turn  to  an  examination  of  the  results 
of  experiments,  —  first  of  the  effects  of  training  one 
function  upon  other  expressions  of  the  same  function, 
and  second  upon  the  transfer  of  training  from  one 
function  to  another.  The  field  that  has  been  best  de- 
veloped is  memory.  It  has  long  been  a  question  whether 
it  is  possible  to  train  one's  capacity  to  remember  facts 
of  one  sort  by  practice  in  learning  some  other  set  of 
facts.  The  first  answer  to  this  question  in  more  recent 
times  was  a  decided  negative.  James  argued  that  in 
learning  one  statement  a  different  tract  in  the  cortex 
must  be  involved  from  that  involved  in  learning  any 
other  and  consequently  training  one  nerve  tract  would 
have  no  more  effect  upon  another  tract  than  would 
practice  in  bending  a  finger  upon  the  ability  to  walk. 
James  also  put  the  opinion  to  practical  proof  by  learn- 
ing a  bit  of  verse,  then  spending  a  month  in  practice 
on  other  poetry,  and  testing  the  efficiency  acquired  by 


380        THE  ESSENTIALS  OF  PSYCHOLOGY 

learning  other  stanzas  of  the  test  material.  He  found, 
on  the  average,  that  there  was  little  if  any  gain  after 
the  long  training  and  concluded  that  memory  cannot 
be  trained. 

More  recent  tests  by  Ebert  and  Meumann  came  to 
the  opposite  conclusion.  They  worked  with  various 
sorts  of  sense  and  nonsense  material.  First,  the  un- 
trained capacity  was  tested  for  one  sort  of  material; 
then,  a  long  period  was  devoted  to  learning  materials 
of  another  kind.  Then  the  first  sort  of  material  was 
learned  again  and  the  ease  of  learning  after  practice  was 
compared  with  the  original.  Other  practice  series  were 
made  and  again  tested.  The  results  showed  that  prac- 
tice with  nonsense  syllables  would  increase  the  ease  of 
learning  philosophical  prose  or  arbitrary  visual  signs  by 
from  50  to  70  per  cent.  They  conclude  that  learning 
anywhere  will  increase  the  efficiency  of  memory  every- 
where, that  practice  in  learning  material  of  any  one 
kind  will  have  a  marked  effect  on  learning  any  other. 
The  conclusion  has  been  criticised  on  the  ground  that 
the  test  series  for  each  sort  of  material  were  so  long 
that  there  was  considerable  opportunity  for  training  in 
them  and  that  a  large  part  of  the  training  must  have 
come  from  practice  in  the  tests,  not  through  transfer 
from  practice  on  other  sorts  of  material.  The  experi- 
ments have  been  repeated  by  Dearborn,  with  the  pre- 
caution of  taking  a  test  series  without  any  training, 
and  comparing  the  results  with  those  after  an  inter- 
vening period  of  training.  The  results  indicate  that 
the  training  has  some  effect  but  not  nearly  so  much  as 
Ebert  and  Meumann  thought.  Probably  the  effect  of 


TRANSFER   OF   TRAINING  381 

training  in  one  field  upon  learning  in  another  will  amount 
to  from  10  to  20  per  cent  as  compared  with  the  50  or 
more  that  Ebert  and  Meumann's  experiments  indicated. 
Training  Memory,  Training  Attention.  —  If  one  asks 
how  learning  one  thing  can  have  an  effect  upon  learning 
something  else  in  spite  of  the  fact  that  the  nervous 
structures  involved  must  be  different  in  each,  the  answer 
undoubtedly  is  to  be  found  in  the  fact  that  learning  of 
any  kind  involves  many  common  factors.  One  must 
always  attend  to  the  material  learned,  and  in  the  experi- 
ments in  question,  one  must  learn  to  attend  under  new 
and  unusual  conditions  and  to  materials  that  one  usually 
has  tried  to  neglect.  The  formation  of  habits  of  attend- 
ing in  general  and  of  attending  to  unusual  materials  and 
under  unusual  conditions  is  the  element  that  serves  to 
facilitate  learning  under  the  different  circumstances  and 
that  may  be  transferred  to  learning  different  material 
under  the  same  circumstances.  In  the  learning  of 
•everyday  life  still  other  common  factors  must  be  recog- 
nised. There  are  many  structural  elements  in  common 
between  things  and  even  between  sciences  called  by 
different  names.  The  same  fact  is  used  in  different 
connections,  and  the  resulting  compound  is  given  a 
different  name  in  each  connection.  For  example,  the 
principles  of  history  are  frequently  similar  to  the  laws 
of  biology,  and  the  spirit  and  attitude  are  very  similar 
in  all  sciences.  All  these  facts  and  principles  learned 
in  one  field  save  time  and  work  in  other  fields.  The 
improvement  in  one  sort  of  memory  acquired  by  train- 
ing some  other  does  not  depend  upon  the  training  of 
some  single  function  or  thing,  but  is  due  to  the  fact 


382        THE  ESSENTIALS  OF  PSYCHOLOGY 

that  learning  anything  develops  habits  of  attending 
and  accustoms  one  to  learn  new  materials  and  under 
new  conditions.  What  is  trained  is  some  common  func- 
tion, not  memory  in  general. 

Transfer  of  Training  in  Discrimination.  —  Very  much 
the  same  result  has  been  obtained  in  experiments  for 
training  discrimination.  It  has  been  shown  by  Coover 
and  Angell  that  discrimination  for  visual  stimuli  is  im- 
proved by  training  in  the  discrimination  of  sounds,  and 
the  quickness  of  response  in  one  way  to  one  sort  of  stim- 
ulus is  increased  by  training  in  another  form  of  response 
to  another  stimulus.  The  effects  of  the  training  again 
may  be  traced  to  the  improvement  in  some  capacity 
common  to  the  two  activities.  Wang  recently  found 
that  practice  in  discriminating  the  length  of  lines  in- 
creased the  ability  to  discriminate  colours  and  tones. 
Measurements  of  the  time  required  to  make  the  com- 
parisons showed  that  the  child  learned  in  the  first  tests 
to  delay  his  judgment  until  sure,  an  acquisition  that 
proved  valuable  in  the  later  tests.  Training  in  the  con- 
trol of  movement  shows  the  same  transfer  from  one  field 
to  another  as  is  demonstrated  for  these  more  intellectual 
capacities  and  activities.  One  may  conclude  in  general 
that  exercise  of  one  sort  tends  ordinarily  to  improvement 
of  related  capacities.  This  rule  is  not  without  excep- 
tions, for  training  may  make  learning  more  difficult  under 
other  circumstances  and  for  certain  sorts  of  activities, 
even  if  they  bear  the  same  name.  An  instance  of  this 
was  cited  in  the  chapter  on  memory.  Common  observa- 
tion indicates  that  training  in  rote  memory  is  likely  to 
interfere  with  skill  in  remembering  ideas,  in  logical 


TRANSFER   OF   TRAINING  383 

memory;  and  vice  versa,  skill  in  remembering  ideas 
may  make  one  neglect  the  words  and  so  make  one  learn 
them  less  easily  than  would  the  untrained  individual. 
The  explanation  reduces  to  the  same  law  as  before. 
What  is  trained  is  a  habit  of  attending,  and  attending 
in  one  way  tends  to  prevent  attending  in  opposed  ways. 
Whether  training  is  harmful  or  beneficial  depends  upon 
whether  some  habit  is  common  to  the  two  processes 
under  discussion,  or  whether  a  habit  established  in  one 
operation  will  be  injurious  in  the  other.  One  can  assert 
at  present  only  that  whether  training  in  one  act  or  in 
one  field  will  be  beneficial  to  other  different  acts  or  in 
other  fields  depends  upon  whether  the  two  functions 
have  anything  in  common,  and  whether  the  common 
factor  works  in  the  same  way  in  each  of  the  activities  in 
question. 

Training  of  General  Intelligence.  —  Still  more  com- 
plicated is  the  problem  and  less  definite  the  result,  when 
one  turns  to  the  question  whether  there  is  anything  in 
common  between  functions  or  capacities  not  of  the 
same  general  kind.  One  of  the  best-known  theories 
asserts  that  a  definite  relation  does  exist  between  skill 
in  any  field  and  the  general  intelligence  of  the  subject. 
It  is  insisted  that  all  capacities  are  sufficiently  inter- 
related to  have  skill  in  one  involve  skill  in  any  other. 
The  facts  upon  which  this  theory  suggested  by  Spearman 
rests  are  now  generally  accepted  as  a  result  of  agreement 
in  the  outcome  of  numerous  investigations.  However, 
many,  if  not  most,  question  the  theory,  which  smacks  of 
faculty  psychology.  Instead  it  is  suggested  that  common 
capacities  are  involved  in  many  seemingly  different  opera- 


384        THE  ESSENTIALS  OF  PSYCHOLOGY 

lions.  The  improvement  in  one  as  a  consequence  of 
training  in  another  rests  upon  use  in  both  of  a  single 
capacity.  At  least  fact  and  theory  agree  that  it  is 
possible  that  training  will  have  some  effect  upon  capaci- 
ties that  have  something  in  common,  but  whether  much 
or  little  can  be  determined  only  by  experiment,  and  satis- 
factory experiments  are  as  yet  lacking. 

Training  from  Subjects  of  School  Curriculum.  —  Still 
farther  are  We  from  being  able  to  assert  that  certain 
subjects  in  the  school  curriculum  will  have  an  effect 
upon  any  particular  capacity,  or  that  one  subject  will 
have  a  greater  effect  than  any  other.  It  is  frequently 
asserted  that  mathematics  trains  reasoning;  classics, 
memory,  and  so  on.  These  assertions  are  based  alto- 
gether on  assumption  and  apparently  assume  an  out-of- 
date  psychology.  Certainly  few  experiments  have  been 
performed  and  no  tests  of  the  effects  of  studying  one 
subject  apart  from  others  have  extended  over  a  suffi- 
ciently long  time  to  give  trustworthy  results.  From 
general  considerations  it  is  evident  that  the  results  of 
studying  any  subject  will  depend  in  very  large  degree 
upon  how  it  is  studied  and  how  it  is  taught.  Mathe- 
matics may  be  made  a  mere  exercise  in  memory,  while 
history  or  the  classics  when  studied  by  suitable  methods 
may  be  primarily  training  in  reasoning.  The  most  that 
may  be  said  with  certainty  is  that  the  sort  of  training 
derived  from  any  subject  will  depend  more  upon  the 
way  it  is  taught  than  upon  the  subject.  Any  subject 
may  give  any  type  of  training,  and  probably  all  forms  in 
some  degree,  but  how  much  depends  upon  circumstances 
that  cannot  be  determined  from  the  name  of  the  subject. 


THE   INTERRELATION   OF   MENTAL  FUNCTION        385 

At  present  it  is  not  possible  to  say  how  far  any  activity 
may  be  prepared  for  by  any  subject  in  the  curriculum. 
Summary.  —  The  outcome  of  the  discussion  of  how 
far  doing  one  thing  is  a  training  for  something  else  has 
been  very  unsatisfactory.  Training  gained  by  doing 
any  one  thing  will  be  in  some  degree  general,  and  will 
aid  in  doing  anything  else  in  the  same  field.  How  much 
it  will  aid,  or  whether  it  will  aid  at  all,  depends  upon 
how  much  there  is  in  common  between  the  two  opera- 
tions, and  this  can  be  determined  only  by  experiment. 
Very  much  the  same  answer  must  be  given  to  the  ques- 
tion how  far  exercise  of  one  function  has  an  effect  upon 
others.  There  may  be  some  effect  or  there  may  be 
none,  according  to  the  relation  of  the  two  functions. 
There  is  little  evidence  of  any  single  function  or  faculty, 
like  general  intelligence,  that  may  be  developed  by  all 
sorts  of  training  and  be  applicable  in  all  fields.  The 
most  that  can  be  said  positively  is  that  one  may  best 
prepare  one's  self  to  do  anything  by  doing  that  thing. 
It  does  not  follow  that  doing  that  thing  will  be  the 
best  preparation  for  life,  or  for  success  in  any  other 
capacity,  but  certainly  skill  in  that  function  can  be 
most  surely  acquired  by  practising  it  directly.  A  gen- 
eral training  is  indispensable,  not  because  it  gives  com- 
mand of  a  particular  trade  or  profession,  but  because 
anything  can  be  understood  fully  only  in  terms  of  other 
things,  and  because  highest  success  is  possible  only 
when  preparation  has  been,  not  for  one  task  alone,  but 
for  many  tasks  of  a  related  kind,  —  for  all  in  fact  that 
have  any  bearing  upon  the  chosen  career.  The  main 
outcome  is  to  enforce  conservatism  in  asserting  just 


386        THE  ESSENTIALS  OF  PSYCHOLOGY 

how  best  to  obtain  a  general  training.  The  one  assured 
result  is  that  training  for  any  particular  task  or  opera- 
tion can  be  acquired  by  doing  that  particular  thing. 

If  the  discussion  has  served  to  emphasise  the  fact 
that,  on  the  one  hand,  mind  is  not  a  collection  of  unre- 
lated faculties  and,  on  the  other,  that  it  is  not  a  single 
force  or  faculty,  but  rather  that  mind  is  merely  a  term 
applied  to  a  number  of  different  functions  spoken  of 
collectively,  the  time  will  have  been  well  spent.  When 
certain  of  these  separate  functions  are  grouped  in  one 
way  or  to  the  attainment  of  one  end,  the  process  is 
perception;  when  grouped  in  another  way,  imagina- 
tion ;  in  a  third,  memory ;  and  in  a  fourth,  reasoning. 
When  other  functions  are  introduced  and  practical 
activities  are  controlled,  the  process  is  will.  Other 
modifications  constitute  the  emotional  and  affective 
processes.  In  any  event,  what  gives  the  name  to  the 
function  in  everyday  life  and  in  scientific  usage  is  not 
the  materials  of  which  the  mental  state  is  composed  or 
even  the  laws  revealed  in  its  operation,  but  the  end  that 
the  function  subserves.  The  fundamental  laws  of  opera- 
tion and  the  simple  elements  are  relatively  few  as  com- 
pared with  the  ends  and  the  names  for  functions  or 
'  faculties/  either  popular  or  scientific.  The  division 
of  the  treatment  of  psychology  into  chapters  devoted 
to  these  particular  functions  is  for  convenience.  The 
functions  themselves  are  not  distinct. 

QUESTIONS 

i.  What  is  meant  by  a  faculty  in  psychology?  State  objec- 
tions to  the  use  of  the  term. 


THE   INTERRELATION   OF   MENTAL  FUNCTION        387 

2.  Define  mental  function.    How  many  mental  functions  would 
you  ascribe  to  man  ?     How  is  a  function  different  from  a  faculty  ? 

3.  Can  you  train  will?    In  what  sense  do  you  use  the  term  in 
your  answer? 

4.  Would  training  in  recognising  flowers  make  one  more  ac- 
curate in  recognising  animals?    What  would  you  assume  in  your 
answer  concerning  partial  identity  of  the  functions  involved? 

5.  What  could  one  mean  by  general  intelligence?    Can  it  be 
trained  if  it  exists  ? 

6.  What  training  do  you  expect  from  mathematics?    from 
history?   from  Latin?   from  physics?   from  psychology?    Would 
it  be  more  in  any  case  than  the  accumulation  of  facts?    What 
changes  might  be  common  to  all? 

REFERENCES 

ANGELL,  PILLSBURY,  JUDD  :  Formal  Discipline.    Educational  Re- 
view, June,  1908,  p.  31. 
ROYCE  :  Outlines  of  Psychology,  pp.  54-56. 
W.  H.  HECK  :  Mental  Discipline. 
COLVIN  :  The  Learning  Process. 

THORNDIKE  :  Educational  Psychology,  vol.  ii,  chs.  xi,  xii. 
WANG  :  Value  of  Sense  Training  in  Children. 


CHAPTER  XVI 
THE  TYPES  OF  MIND 

IN  practical  life  we  are  constantly  making  rough 
classifications  of  men.  One  hears  frequently  that  A 
is  a  man  of  genius,  B  has  good  reasoning  ability  but 
little  memory,  C  has  exceptional  intelligence  but  lacks 
push,  etc.  Obviously,  if  these  types  exist,  psychology 
should  be  in  a  position  to  determine  their  presence 
scientifically,  to  measure  the  differences  between  in- 
dividuals in  these  various  respects,  and  group  them  more 
or  less  accurately.  The  practical  advantages  of  knowing 
the  capacities  of  individuals  would  be  enormous.  Could 
we  tell  in  advance  of  trial  that  a  man  were  to  fail  in  one 
employment  we  might  spare  his  employer  the  expense  of 
training  him  and  the  man  himself  the  pains  of  failure 
and  the  waste  of  time  involved  in  preparation.  Could  a 
state  know  definitely  or  even  within  wide  limits  the 
capacities  of  its  citizens,  it  might  make  sure  that  each 
entered  the  profession  or  occupation  for  which  he  was 
best  adapted  and  avoid  educating  men  for  fields  in 
which  they  could  not  succeed. 

Conceivably  men  might  be  different  in  degree  of 
ability,  in  kind  of  ability,  and  in  the  different  degrees  in 
which  the  different  kinds  of  ability  were  present  in  each. 
There  might  be  individuals  who  were  stupid  in  every 
respect,  others  who  were  geniuses,  and  others  of  moderate 


THE   PROBLEM   OF   TYPES  389 

ability.  On  the  other  hand  one  might  have  men  who 
could  reason  without  remembering  much,  others  of  con- 
structive ability,  but  with  little  knowledge,  etc.  Were 
either  of  these  latter  groupings  of  abilities  common,  it 
might  well  be  that  one  could  discover  fixed  types  or 
combinations  of  abilities  and  that  it  would  be  possible, 
first  to  determine  the  number  of  types  and  then  to  dis- 
cover some  means  of  recognising  to  which  type  any 
individual  belonged  without  trying  him  in  all  of  the 
different  respects.  It  has  been  suggested  by  psycholo- 
gists that  one  may  distinguish  a  slow  type  with  ability 
to  concentrate  closely  as  opposed  to  a  quick,  easily 
distracted  type,  —  that  one  would  acquire  slowly,  forget 
slowly,  and  reason  well,  while  the  other  would  learn 
quickly,  forget  quickly,  and  reach  conclusions  by 
intuition.  Other  types  have  been  assumed,  all  in 
advance  of  test  or  on  inadequate  test. 

If  we  are  to  solve  any  of  these  problems  large  numbers 
of  individuals  must  be  thoroughly  investigated  with 
reference  to  many  of  their  capacities,  then  the  different 
ways  in  which  their  abilities  are  combined  must  be 
studied  to  determine  what  capacities  are  found  together. 
The  two  problems  as  to  whether  there  are  types  of  in- 
dividuals or  whether  individuals  are  all  of  one  type  with 
only  differences  in  general  ability  are  closely  related. 
If  there  are  types  the  problem  is  very  complicated,  if 
there  are  not  types  we  can  classify  all  on  the  basis 
of  degree  of  ability  and  measure  that  ability  in  any 
way  we  please,  on  the  assumption  that  degree  of  success 
in  one  test  will  give  the  relative  standing  in  all  other 
respects  as  well.  This  first  problem  may  be  attacked 


39°  THE   ESSENTIALS    OF   PSYCHOLOGY 

first,  as  upon  the  answer  to  it  depends  the  degree  of 
importance  that  may  attach  to  the  solution  of  the 
second. 

Are  There  Different  Types  of  Individuals?  —  An 
answer  to  the  first  question  has  been  sought  in  two 
ways :  (i)  by  testing  a  number  of  individuals  in  several 
different  capacities  and  determining  what  the  chances 
are  that  an  individual  who  stands  high  in  one  respect 
will  stand  high  in  others ;  (2)  by  obtaining  the  opinions 
of  different  men  as  to  the  relative  standing  of  others  in  a 
number  of  characteristics  and  then  making  a  similar 
determination  of  the  relation  between  standing  in 
different  qualities.  In  either  case,  special  statistical 
methods  are  necessary  to  determine  what  the  relation 
may  be  between  the  traits  after  we  have  either  estimated 
or  measured  the  standing  of  each  individual  in  each 
trait.  The  problem  would  not  arise  were  all  individuals 
to  have  exactly  the  same  relative  rank  in  each.  Were 
we,  e.g.  in  comparing  the  relation  between  memory 
span  and  ability  to  solve  problems  in  geometry,  to  find 
that  the  individual  who  stood  first  in  the  one  was  also 
first  in  the  other,  and  that  he  who  stood  second  in  one 
was  second  in  the  other,  etc.,  all  the  way  through,  there 
would  be  no  difficulty.  As  it  is,  however,  all  that  we  can 
ever  expect  is  that  many  of  those  above  the  average  in 
one  will  also  be  above  the  average  in  another  respect,  and 
we  need  a  way  of  measuring  the  probable  relationship 
when  some  are  above  in  both,  while  others  are  above 
in  one  and  below  in  another. 

The  Coefficient  of  Correlation.  —  Without  giving  the 
formula  used,  which  may  be  found  in  any  of  the  works  on 


THE   TYPES   OF   MIND  391 

measurement  methods,1  we  may  say  that  by  comparing 
the  position  of  each  individual  above  or  below  the  average 
standing  of  all  in  each  of  two  tests  or  traits,  we  obtain  a 
ratio,  that  indicates  the  degree  of  likelihood  that  an 
individual  who  possesses  one  trait  in  high  degree  will 
possess  others  also  in  large  amount.  This  ratio  is  called 
the  coefficient  of  correlation.  Were  all  individuals  to 
have  exactly  the  same  standing  in  each  trait,  the  coeffi- 
cient of  correlation  would  be  +  i ;  were  the  individuals 
who  stood  in  one  order  in  one  trait  to  have  exactly  the 
opposite  order  in  the  other,  the  coefficient  would  be  —  i. 
Where  the  relation  between  the  traits  is  close  it 
approaches  +  i,  where  it  is  slight  it  approaches  zero. 
A  zero  coefficient  means  that  there  is  no  relation  between 
the  traits  and  that  it  is  not  possible  to  infer  anything 
from  the  standing  of  an  individual  in  one  trait  as  to  how 
he  would  stand  in  another.  The  coefficient  seldom  rises 
above  .90  even  when  the  two  capacities  compared  seem 
to  be  exactly  the  same,  as  when  one  measures  the 
accuracy  of  comparing  weights  of  different  magnitudes, 
or  the  ability  to  discriminate  horizontal  lines  and  the 
ability  to  discriminate  vertical  lines.  On  the  other  hand 
correlations  under  .35  usually  have  little  significance. 

All  Men  Are  of  the  Same  General  Type.  — The  results 
of  the  different  tests  all  agree  in  indicating  that  excellence 
in  any  desirable  trait  is  closely  correlated  with  excellence 
in  all  other  desirable  traits.  Thus  there  is  a  positive 
correlation  between  memory  and  quickness  in  sorting 
the  alphabet,  between  sorting  cards  and  discriminating 

1  G.  M.  Whipple :  '  Manual  of  Mental  and  Physical  Measurements,' 
vol.  i,  pp.  35-51. 


3Q2  THE  ESSENTIALS   OF  PSYCHOLOGY 

weights,  in  fact  between  all  of  the  desirable  qualities 
that  have  been  carefully  measured  and  compared.  If 
we  translate  this  statement  into  our  everyday  expres- 
sion, the  all  round  man  is  the  rule,  the  man  of  one- 
sided development,  the  exception.  More  than  this  our 
present  knowledge  is  not  sufficient  to  show.  The  innate 
differences  between  types  either  are  not  sufficiently 
marked,  or  the  combinations  of  traits  are  so  numerous 
and  so  many  different  arrangements  result  that  we  have 
not  yet  been  able  to  discover  and  formulate  even  the 
most  frequently  occurring  among  them. 

Character  Closely  Correlated  with  Intelligence.  —  The 
method  of  estimating  the  relative  amounts  of  certain 
traits  possessed  by  different  individuals  was  applied 
extensively  by  Webb.1  He  asked  several  instructors  to 
grade  a  large  number  of  boys  with  reference  to  the  more 
characteristic  intellectual  traits,  and  also  on  a  series  of 
more  general  traits,  *  tendency  not  to  abandon  tasks  in 
the  face  of  obstacles/  '  tendency  not  to  abandon  tasks 
from  mere  changeability/  '  kindness  on  principle/ 
'  trustworthiness/  '  conscientiousness/  '  readiness  to 
become  angry/  '  eagerness  for  admiration/  and  '  bodily 
activity  in  the  pursuit  of  pleasure.'  When  these  were 
correlated  with  each  other  it  was  found  that  the  first 
five  showed  a  high  correlation,  —  an  individual  who  was 
preeminent  in  one  would  be  likely  to  be  well  favoured 
in  the  others  also,  while  they  showed  a  negative 
correlation  with  the  last  three.  The  last  three  also 
correlated  closely  with  each  other.  Webb  argued  from 

1  Edward  Webb:  Character  and  Intelligence,  British  Journal  of 
Psychology,  Monograph  Supplements,  III. 


ABILITY  IS   UNITARY  393 

these  results  that  we  must  recognise  two  groups  of 
traits,  an  intellectual  and  what  he  calls  the  character 
group,  which  depends  upon  what  are  popularly  known  as 
the  volitional  and  emotional  characteristics.  The  desir- 
able traits  in  each  are  likely  to  be  found  together. 
Between  the  two  groups  the  correlations  are  not  so  close 
as  they  are  between  traits  within  each  group,  but  even 
here  the  more  desirable  characteristics  show  some 
correlation.  On  the  whole  the  man  with  the  better 
intelligence  is  also  the  better  tempered  and  has  the  better 
qualities  of  leadership  and  persistence. 

Interpretation  of  Results.  —  Both  methods  seem  to  be 
at  one  in  the  positive  statement  that  excellences  in  all 
desirable  respects  tend  to  be  found  together.  How 
this  shall  be  interpreted  is  not  quite  so  clear.  It  may 
be  due  either  to  the  presence  of  some  common  quality 
in  all  mental  operations,  possessed  by  each  individual 
in  varying  degrees.  As  was  seen  in  the  preceding  chap- 
ter, Spearman  has  suggested  that  we  may  say  that  there 
is  what  may  be  called  general  intelligence,  and  that 
an  individual  who  has  much  of  it  will  show  all  desirable 
traits  in  high  degree.  Its  possession  in  high  degree  makes 
all  accomplishment  easy,  its  presence  in  slighter  amount 
reduces  capacity  in  any  field.  The  other  alternative 
explanation  would  assume  a  number  of  traits  which  are 
required  for  success  in  each  of  the  tests.  Thus,  if  we 
assume  a  native  retentiveness,  acuity  of  the  different 
senses,  quickness  of  reviving  associates,  and  motor 
quickness  as  fundamental  traits,  such  a  test  as  marking 
the  a's  on  a  page  of  print  might  involve  at  least  three, 
probably  four,  and  almost  any  other  test  that  might  be 


394  THE  ESSENTIALS   OF   PSYCHOLOGY 

given  would  employ  more  than  one.  High  standing 
in  any  test  might  then  be  due  to  the  excellence  of  any 
one  of  these  capacities  and  the  fact  that  excellence  in 
one  was  likely  to  imply  excellence  in  all  might  be  due 
either  to  the  fact  that  high  development  of  one  capacity 
might  make  up  for  lack  in  others,  or  that  there  was 
something  that  made  it  likely  that  the  presence  of  one  in 
high  degree  would  also  imply  the  presence  of  the  others 
in  high  degree.  As  no  one  pretends  to  know  how  many 
fundamental  capacities  there  are  nor  what  the  nature 
of  their  interrelations  may  be,  speculation  on  the  point 
is  not  very  fruitful.  We  must  for  the  present  content 
ourselves  with  the  raw  results  that  high  standing  in 
one  respect  is  likely  to  go  with  high  standing  in  all 
others  as  well.  Whether  this  is  because  there  is  some  one 
capacity  common  to  all  activities  or  a  number  of  rela- 
tively simple  capacities,  several  or  all  of  which  com- 
bine in  each  of  the  activities  to  which  we  give  special 
names,  we  do  not  as  yet  know. 

As  to  how  far  we  may  distinguish  between  what  are 
ordinarily  called  the  intellectual  and  the  voluntary  and 
emotional  characteristics  which  combine  to  give  what 
we  popularly  call  character  we  have  less  evidence. 
Webb's  results  stand  alone  on  the  scientific  side.  They 
would  indicate  that  part  of  a  man's  success  depends  upon 
intelligence,  part  upon  a  pertinacity  and  tendency  to  be 
more  or  less  guided  by  desire  or  pleasure.  Popular 
observation  indicates  that  part  of  a  man's  effectiveness 
depends  upon  pure  intellectual  capacity  and  part  upon 
the  use  that  he  makes  of  his  ability,  including  his 
willingness  to  exert  himself  to  learn  and  to  apply  his 


THE    DISTRIBUTION   OF   INTELLIGENCE  395 

knowledge  and  the  positiveness  with  which  he  expresses 
his  conclusions.  In  the  estimates  of  an  officer's  ability  on 
his  personnel  card,  there  is  a  place  for  an  estimate  of 
personality  which  includes  leadership  and  tact,  qualities 
which  would  come  under  our  emotional  and  voluntary 
traits.  These  are  accepted  as  quite  as  important  for 
success  as  intelligence.  One  may  fail  for  lack  of 
either.  Mrs.  Woolley  found  that  these  volitional 
and  emotional  traits  were  almost  as  important  as 
intelligence  as  determined  by  test  in  deciding  what 
wages  would  be  earned  by  children  who  leave  the 
public  schools.  These  qualities  are  fairly  closely  cor- 
related with  intelligence  according  to  all  tests.  This 
is  what  would  be  expected  from  the  fact  that  appre- 
ciation of  the  ends  of  life  and  the  necessity  for  en- 
deavour to  attain,  them  is  a  large  element  in  keeping  a 
man  at  work. 

The  Distribution  of  Intelligence.  —  The  answer  to  the 
question  how  ability  is  distributed  in  the  population  is 
made  easier  by  the  facts  already  presented  that  ability 
is  of  one  kind,  or  that  men  of  good  ability  in  one  respect 
are  likely  to  possess  good  capacities  in  all.  Can  we 
determine  a  man's  capacity  in  one  respect  we  shall  have 
a  close  approximation  to  his  capacity  in  all.  It  is  not 
necessary  to  measure  him  in  all  the  tasks  to  which  he  must 
apply  himself,  but  we  may  measure  him  in  one  or  a 
few  and  obtain  his  approximate  rank  for  all.  While 
most  systems  of  measurement  apply  several  tests  that 
are  supposed  to  involve  different  processes,  probably 
the  main  value  of  using  more  than  one  test  is  to  give  an 
average  of  performance  that  shall  eliminate  as  many  as 


396  THE  ESSENTIALS   OF   PSYCHOLOGY 

possible  of  the  chance  variations  in  the  condition  of  the 
subject  and  of  his  environment. 

The  Curve  of  Distribution.  —  Two  fundamental 
assumptions  that  are  made  in  all  biological  measurements 
must  be  accepted  as  a  basis  of  psychological  tests. 
The  first  is  that  in  any  chance  collection  of  individuals 
of  reasonable  size  there  will  be  represented  the  range  of 
qualities  for  all  of  the  species.  In  our  application  if  we 
select  by  chance  a  hundred  or  a  thousand  individuals, 
measurements  made  upon  them  will  hold  approximately 
of  the  entire  population.  The  larger  the  number  in- 
cluded in  the  sample,  the  more  accurately  will  the  selec- 
tion approximate  the  result  that  would  be  obtained 
from  measuring  all.  The  second  general  assumption  is 
that  in  any  large  group  all  characters,  including  mental 
capacity,  are  distributed  as  are  errors  in  reading  scales 
or  as  shots  at  a  target.  We  may  emphasise  two  im- 
portant characteristics  of  such  a  grouping.  One  is 
that  there  are  just  as  many  above  as  below  the  average, 
that  the  distribution  is  symmetrical,  and  the  other 
that  the  greater  the  degree  of  divergence  from  the 
average,  the  fewer  individuals  there  will  be  who  show 
this  deviation.  Thus  according  to  Bertillon  the  stature 
of  a  thousand  Frenchmen  would  be  distributed  about 
164^  cm.,  with  236  between  163  and  166,  198  each  be- 
tween 159  and  162  cm.  and  between  167  and  170,  148 
between  153  and  158  and  171  and  176,  and  only  36  at 
each  extreme  between  141  and  152  and  between  177  and 
188.  There  would  be  10  each  below  141  and  above  188. 
The  curve  which  would  show  the  distribution  of  any 
physical  measurement  would  have  approximately  the 


THE    DISTRIBUTION   OF    INTELLIGENCE  397 

same  form.  It  is  shown  in  Figure  35.  It  will  be  noticed 
from  the  figures  given  that  there  are  about  eighty  who 
are  within  a  centimetre  of  each  other  in  height  within 
the  three  central  centimetres  and  an  average  of  three 
who  are  within  a  centimetre  of  the  same  height  at 
either  extreme  of  ten  centimetres. 


FIG.  35.  —  The  distribution  of  stature  among  French  soldiers.  The  distances 
on  the  horizontal  axis  indicate  the  height  in  centimetres,  on  the  vertical  axis, 
the  number  of  men  of  heights  between  the  figures  printed  below  the  line. 
From  Bertillon  :  '  Instructions  signaletiques.' 

Methods  of  Grading  Intelligence.  —  We  have  every 
reason  to  believe  that  the  same  general  rules  hold  for 
the  distribution  of  intelligence.  It  has  so  far  not  been 
possible  to  use  any  measure  of  intelligence  for  which  we 
can  be  sure  that  all  steps  are  of  equal  difficulty.  Re- 
membering eight  digits  is  much  more  than  a  third  harder 
than  remembering  six  digits,  and  no  one  can  say  how  much 
more  intelligent  a  man  is  who  can  give  an  associate 
in  an  average  of  half  a  second  than  one  who  can  give  one 
in  an  average  of  one  second.  Certainly  he  is  much  more 


398        THE  ESSENTIALS  OF  PSYCHOLOGY 

than  twice  as  high  in  the  scale  if  either  difficulty  or 
frequency  of  appearance  is  used  as  a  measure.  Attempts 
have  been  made  to  measure  intelligence  in  three  ways, 
each  of  which  has  certain  advantages  and  certain  dis- 
advantages. The  first,  most  frequently  used,  is  by 
comparing  the  individual  to  be  measured  with  others 
in  a  group,  on  the  first  of  our  assumptions  that  a  sample 
may  be  regarded  as  typical  of  a  whole  class.  If  one 
may  assign  a  man  to  a  certain  position  in  a  class  of  one 
hundred  there  is  approximate  certainty  that  he  will  have 
about  the  same  position  with  reference  to  all  individuals 
selected  in  the  same  general  way.  This  is  the  basis  of 
relative  markings  in  school  and  college  classes.  If 
you  grade  a  man  as  belonging  in  the  upper  tenth  in  a 
class  of  one  hundred,  you  may  feel  assured  that  he  will 
have  a  place  in  the  upper  tenth  of  the  community  as  a 
whole.  Since  relative  ranking  among  individuals  known 
well  is  fairly  accurate,  estimates  of  this  kind  based  on 
daily  accomplishment  and  examination  are  a  reliable 
index  of  the  intelligence.  The  exception  conies  only 
when  the  group  in  which  the  ranking  is  made  is 
not  representative,  which  happens  when  some  force 
other  than  chance  has  been  operative  in  selecting  it. 
Thus  a  man  marked  in  the  average  of  a  college  class 
would  very  probably  still  stand  among  the  best  tenth 
of  the  general  population,  because  the  men  who  go  to 
college  have  been  selected  by  success  in  the  schools, 
have  on  the  whole  more  successful  fathers  and  probably 
more  intelligent  parents  than  the  average.  The  chances 
are  large  that  a  man  who  stands  in  the  upper  tenth  in  a 
class  of  one  hundred  in  one  university  will  also  stand 


THE   DISTRIBUTION   OF   INTELLIGENCE  399 

among  the  upper  tenth  in  another  university.  Relative 
grades  are  on  the  whole  absolute  grades  as  well.  While 
this  assumption  works  as  a  means  of  determining  the 
ability  of  any  individual  it  assumes  rather  than  proves 
that  ability  is  distributed  in  accordance  with  the  curve 
of  probability. 

Mental  Tests.  —  The  second  method  used,  grading  by 
accomplishment  in  some  standard  task,  suffers,  as  was 
said  above,  from  the  fact  that  so  far  we  have  no  tasks 
that  can  be  adjusted  to  give  equal  steps,  and  no  knowledge 
as  to  how  different  attainments  in  various  parts  of  a 
test  may  be  compared.  One  should  obtain  a  series  of 
tasks  that  depends  very  little  upon  past  training,  that 
is  difficult  enough  to  require  effort  from  the  best  and  not 
too  hard  for  the  most  poorly  endowed  to  accomplish 
something  with  it.  If  then  we  could  determine  what 
constitutes  equal  steps  in  difficulty  we  would  have  an 
ideal  test.  Groups  of  tests  of  this  type  were  developed 
for  testing  men  drafted  during  the  last  war  and  applied 
to  a  million  and  three-quarters  individuals.  It  seems  to 
be  satisfactory  in  meeting  the  first  two  of  our  criteria; 
and  using  the  assumption  that  intelligence  is  distributed 
as  are  physical  characteristics,  one  may  gauge  the  diffi- 
culty of  the  tests.  The  group  includes  tests  for  quick- 
ness and  control  of  associations,  for  ingenuity  in  verbal 
and  manual  operations,  and  for  retention. 

Using  the  distribution  curve  and  accomplishments  in 
the  tests  and  previous  attainments,  we  find  that  among 
the  men  drafted  four  or  five  per  cent  belong  in  an  A  group, 
men  who  can  do  superior  work  in  a  university  and  make 
higher  officers  if  they  possess  leadership  and  initiative ; 


400        THE  ESSENTIALS  OF  PSYCHOLOGY 

eight  or  ten  per  cent  to  a  '  B  '  grade,  men  who  are  capable 
of  doing  average  work  in  college  and  of  making  successful 
officers ;  about  sixty  per  cent  to  a  '  C '  grade  composed 
of  men  of  average  intelligence.  This  grade  is  divided 
again  into  '  C  + '  of  eighteen  per  cent  who  are  good  high 
school  men,  but  men  who  would  not  do  well  in  college, 
a '  C '  grade  of  twenty-five  per  cent,  and  a  '  C  — '  grade  of 
twenty  per  cent.  Measured  in  school  accomplishment 
the  '  C '  would  not  do  well  in  high  school  work,  the  '  C  — ' 
is  of  grade  school  intelligence.  A  '  D  '  grade  of  fifteen 
per  cent  is  of  normal  men  of  sufficient  intelligence  to 
make  good  privates.  About  one  per  cent  was  graded 
as  '  D  — '  or '  E,'  and  was  made  up  of  men  who  could  not 
rise  above  the  third  or  fourth  grade  in  school.1  This 
classification,  as  was  said,  assumes  rather  than  proves 
the  distribution  according  to  the  law  of  probability, 
but  the  assumption  squares  well  with  attainments  in 
other  lines  and  is  at  least  not  out  of  harmony  with  what 
we  know  in  this  and  other  connections. 

The  Binet  Scale.  —  The  first  generally  used  system 
of  testing  intelligence  was  developed  by  Binet  and 
Simon.  The  essentials  of  the  method  consist  in  com- 
paring the  accomplishments  of  the  individuals  in  several 
tests  with  those  of  children  of  different  ages.  They 
selected  a  series  of  very  simple  tests  and  determined 
by  trial  upon  a  large  number  of  children  what  the  average 
child  of  a  given  age  could  do.  The  same  tests  are  given 
to  the  individual  to  be  tested  and  his  results  checked 
against  those  of  a  child  of  a  given  age.  On  this  basis  it 

1Terman:  'Use  of  Intelligence  Tests  in  the  Army,'  Psychological 
Bulletin,  Vol.  15,  pp.  177-187. 


THE   DISTRIBUTION   OF   INTELLIGENCE  401 

is  possible  to  assert  of  any  individual  that  he  has  an 
intelligence  equal  to  that  of  a  child  of  eight  or  ten,  or 
five.  For  convenience  we  speak  of  this  as  his  '  mental 
age.'  Thus  we  may  say  that  the  men  who  grade  '  D  — ' 
in  the  army  tests  are  below  the  mental  age  of  ten. 
For  the  lower  grades  of  intelligence  these  tests  with  their 
modifications  have  proved  very  satisfactory.  The 
main  objection  to  them  in  connection  with  our  present 
problem  of  the  distribution  of  intelligence  is  that  we 
have  no  assurance  that  a  child  increases  in  intelligence 
the  same  amount  in  each  year,  but  it  probably  more 
nearly  approximates  an  equal  step  than  any  of  the 
accomplishment  tests  that  we  have.  Measurements  by 
the  scale  indicate  that  distribution  for  the  lower  grades 
is  in  accordance  with  the  probability  curve,  modified 
somewhat  by  the  fact  that  physical  accidents  all  tend  to 
lower  the  intelligence  of  an  individual,  never  to  raise  it. 
The  Lower  Grades  of  Intelligence.  —  This  method 
has  been  applied  with  success  in  determining  the  ability 
of  children  for  practical  school  purposes,  and  in  selecting 
the  individuals  of  subnormal  intelligence  from  the 
normal  among  the  criminal  and  pauper  classes.  For 
convenience  in  nomenclature  it  has  become  customary 
to  make  a  classification  into  three  groups  on  the  basis 
of  these  age  determinations.  Individuals  of  a  mental 
age  of  two  or  less  are  called  idiots,  those  of  a  mental  age 
between  two  and  seven  are  called  imbeciles,  and  those 
from  eight  to  twelve  are  called  morons  from  the  Greek 
word  for  fool.  The  idiots  are  incapable  of  living  with- 
out constant  attention;  the  imbeciles  require  institu- 
tional care  in  practically  every  case,  but  can  satisfy 


402  THE    ESSENTIALS    OF   PSYCHOLOGY 

their  own  physical  needs,  while  the  morons  may  seem 
normal  or  merely  dumb  witted,  but  cannot  compete 
on  equal  terms  in  the  struggle  for  existence  and  are  in 
many  cases  a  menace  to  society  through  their  lack  of 
self-restraint.  They  constitute  a  large  percentage  of  the 
criminal  and  pauper  class. 

The  Problem  of  the  Feeble-minded.  —  It  is  estimated 
that  from  one-half  to  one  per  cent  of  the  population  is 
found  in  the  three  classes  of  defectives.  In  the  army 
tests  of  a  little  more  than  a  million  men  more  than  16,000 
had  a  mental  age  of  eight  or  less,  and  more  than  7000 
of  less  than  seven.  Of  course  the  more  obvious  cases  had 
been  sent  to  institutions  earlier  or  were  rejected  by  the 
examining  physicians.  The  mentally  deficient  individ- 
uals constitute  a  constant  problem  for  the  schools  and  for 
the  courts.  Many  of  the  children  who  are  constantly 
falling  behind  in  the  schools  prove  on  test  to  belong  to 
the  feebly  endowed.  They  cannot  learn  the  ordinary 
materials  or  by  the  methods  of  the  normal  children. 
If  they  are  to  be  taught  they  must  be  given  special 
training  and  in  many  cases  can  learn  to  advantage  only 
the  more  mechanical  operations.  Many  of  these  children 
graduate  from  the  schools  to  the  police  courts  or  poor- 
houses  after  a  longer  or  shorter  period  of  unsuccessful 
struggle  with  the  world.  Tests  of  the  inmates  of  reform 
schools,  work  houses,  jails,  and  penitentiaries  in  various 
parts  of  the  United  States  show  that  from  twenty  to 
forty  per  cent  are  below  the  mental  age  of  twelve. 
They  are  criminals  because  of  a  defect  of  intelligence 
which  prevents  them  both  from  earning  a  living  and 
from  appreciating  the  aims  and  from  being  controlled 


THE   DISTRIBUTION   OF   INTELLIGENCE  403 

by  the  motives  of  normal  individuals.  As  two-thirds 
of  the  feeble-minded  are  descended  from  individuals 
themselves  feeble-minded,  it  is  probable  that  the  condi- 
tion is  inherited  in  most  cases  and  that  all  that  can  be 
done  to  improve  the  situation  is  to  keep  them  in  insti- 
tutions, —  if  possible  in  institutions  where  work  may 
be  provided  that  will  make  them  self-supporting,  — 
where  they  may  be  kept  from  harming  themselves  and 
others,  and  prevented  from  propagating  their  kind.  A 
proper  solution  of  the  problem  of  caring  for  them  will 
have  a  marked  beneficial  influence  upon  the  state  in 
relieving  the  schools  and  preventing  crime  and  pau- 
perism. 

Distribution  of  Higher  Grades  of  Intelligence.  — 
Measurement  of  the  higher  grades  of  intelligence  has 
received  much  less  attention.  Above  twelve  the  age 
gradation  no  longer  has  significance.  This  is  partly  be- 
cause age  after  that  adds  little  to  fundamental  capacity, 
partly  because  the  differences  in  training  in  the  different 
capacities  that  are  tested  tend  to  obscure  the  effects  of 
native  endowment,  partly,  possibly,  because  talent 
begins  to  show  more  diversity.  At  least,  whatever  the 
reason,  there  is  some  evidence  that  the  average  in- 
telligence of  the  mass  is  not  much  above  that  of  the  child 
of  thirteen  as  measured  by  these  Binet  and  other  tests. 
One  set  of  tests  on  a  large  number  of  men  chosen  at 
random  showed  an  average  age  of  twelve  and  a  half, 
while  not  more  than  two  per  cent  of  the  population  is 
below  the  mental  age  of  eleven.  The  army  tests  would 
indicate,  as  said  above,  that  some  four  or  five  per  cent 
of  the  population  would  belong  to  the  highest  grades, 


404        THE  ESSENTIALS  OF  PSYCHOLOGY 

but  whether  this  grade  is  as  much  above  the  average 
as  the  various  types  of  feeble-minded  are  below  we  have 
no  means  of  knowing.  Whipple  has  recently  devised  a 
group  of  tests  which  enable  him  to  select  from  the 
schools  super-normal  children.  Children  selected  in  this 
way  can  accomplish  much  more  than  the  average  child 
and  can  complete  the  work  of  the  grades  in  two  years  or 
more  less  than  the  average  time.  What  evidence  we 
have  puts  about  five  to  eight  per  cent  in  this  superior 
group.  The  results  taken  together  seem  sufficient  to 
justify  the  assumption  that  there  is  a  distribution  of 
the  higher  forms  of  ability  symmetrical  with  the  lower, 
that  the  greater  the  departure  from  the  average,  the 
less  frequent  in  occurrence  are  the  individuals  who  have 
the  degree  of  intelligence  in  question.  We  are  also 
assured  in  drawing  the  inference  that  the  variations  are 
gradual  above  as  below,  that  there  are  no  sharp  lines 
of  division.  The  genius  is  not  a  man  who  stands  in  a 
class  by  himself,  altogether  apart  from  others.  He 
merely  stands  among  a  few  in  the  highest  grades  of  in- 
telligence. While  we  see  marked  specialisation  in 
capacity  in  everyday  life,  most  statistical  and  experi- 
mental studies  emphasise  the  unity  of  ability  —  lead  us 
to  believe  that  a  man  who  shows  superior  ability  in  one 
line  will  be  superior  in  all  or  many  others  if  he  devotes 
himself  to  them.  Differences  between  men  who  suc- 
ceed in  different  departments  may  be  due  to  the  partic- 
ular training  and  particular  opportunities  rather  than 
to  native  endowment.  It  may  be  remarked  that  the 
term  genius  itself  is  open  to  abuse  in  so  far  as  it  im- 
plies the  existence  of  super-men.  The  term  may  be 


THE   TYPES   OF   MIND  405 

regarded  as  a  tribute  paid  to  the  man  who  is  exceptionally 
successful  in  some  one  department.  It  may  be  added 
that  this  superior  intelligence  is  in  considerable  degree 
hereditary.  Galton  and  others  have  shown  that  men 
of  the  higher  grades  of  ability  appear  in  certain  families 
much  more  frequently  than  in  others. 

Practical  Success  Harmonises  with  Experiments.  — 
These  general  conclusions,  that  ability  is  not  specialised, 
that  ability  in  one  field  is  closely  related  to  ability  in 
another,  and  that  special  ability  in  one  large  group  is 
likely  to  indicate  high  standing  in  others  as  well,  hold 
for  observations  and  statistics  of  actual  accomplishment 
as  well  as  for  the  results  of  tests.  Comparison  of 
grades  of  individuals  in  grammar  school,  high  school, 
and  university  shows  that  students  with  a  high 
standing  in  one  have  a  high  standing  in  others  also. 
This  correlation  holds  between  school  standing  and 
accomplishment  in  later  life.  A  man  who  stands  high 
in  his  university  class  has  a  much  greater  chance  of 
obtaining  eminence  than  the  man  of  average  rank.  A 
man  who  has  been  elected  to  the  honorary  society  of 
Phi  Beta  Kappa,  election  given  to  the  men  among  the 
upper  fifth  of  the  class  at  graduation,  is  four  or  five 
times  as  likely  to  appear  in  "  Who's  Who  "  as  are  his 
classmates  of  lower  standing.  Studies  of  the  salaries 
of  graduates  of  an  engineering  school  some  years  after 
graduation  showed  that  there  was  a  close  correlation 
between  salaries  received  and  standing  while  in  college. 
The  statement  that  ability  is  not  specialised  is  strikingly 
confirmed  by  the  fact  that  high  standing  in  the  under- 
graduate college  in  Harvard  College  foreshadows  success 


406        THE  ESSENTIALS  OF  PSYCHOLOGY 

in  the  medical  or  law  school  of  the  university,  whether 
the  subjects  studied  are  or  are  not  closely  connected  with 
the  later  work. 

While  we  cannot  emphasise  too  strongly  this  general 
statement  that  ability  is  all  of  one  kind,  it  is  at  the  same 
time  well  to  admit  that  denial  of  a  specialised  ability 
rests  upon  negative  grounds  alone,  that  it  is  safer  to  say 
that  we  have  not  yet  discovered  different  types  of  mind 
than  to  assert  that  they  do  not  exist.  Certainly  in  every- 
day life  we  find  men  who  succeed  in  business  who  did  not 
do  well  in  the  university,  and  men  who  do  very  well  in 
specialised  professions  who  were  of  only  moderate  ability 
in  the  professional  school.  They  will  not  infrequently 
win  fame  where  their  fellow  of  higher  standing  is  only 
moderately  successful.  These  cases  may  be  explained 
in  two  ways.  In  the  first  place,  our  general  statements 
hold  only  in  the  long  run  and  on  the  average.  Many 
exceptions  are  admitted  in  the  averages.  These  are 
lost  in  the  general  statement,  are  outweighed  by  the 
great  majority,  while  just  because  they  are  exceptions 
they  are  likely  to  attract  the  ordinary  observer.  In  the 
second  place,  the  differences  may  be  due  to  training. 
The  general  belief  in  types  may  thus  be  due  to  mistaking 
the  exception  for  the  rule,  it  may  be  due  to  mistaking 
success  due  to  special  training  or  to  special  opportunity 
for  success  due  to  special  aptitude,  or  it  may  be  due  to 
failure  on  the  part  of  psychologists  to  devise  tests  that 
will  discover  special  aptitudes,  and  lack  of  investigations 
of  the  ways  in  which  they  may  be  combined.  It  is 
altogether  possible  that  the  relatively  few  studies 
published  have  not  happened  to  hit  upon  the  proper 


THE   TYPES   OF  MIND  407 

methods  or  have  not  been  sufficiently  detailed  to  discover 
differences  which  may  be  slight  and  still  in  the  main  con- 
stitute types  of  intellect.  Certain  it  is  that  popular 
belief  in  the  existence  of  groups  of  traits  in  individuals 
that  constitute  them  distinct  types  is  strong,  and  one 
cannot  be  equally  certain  that  the  psychological  studies 
are  sufficiently  advanced  to  dispute  this  belief.  It  seems, 
then,  that  we  may  feel  fairly  well  assured  that  all  forms 
of  excellence  in  mental  capacity  are  closely  correlated, 
that  a  man  who  stands  well  in  one  capacity  is  likely  to 
stand  well  in  all.  That  there  are  numerous  differences 
in  the  grades  of  accomplishment  in  different  lines  is 
equally  certain.  So  far,  however,  we  are  not  able  to  sort 
forms  of  capacities  into  distinct  groups.  There  probably 
are  many  of  these  types,  —  certainly  no  two  men  are 
alike  in  all  particulars,  —  how  many  we  are  simply  not 
able  to  say.  Furthermore  we  cannot  say  to  what  these 
differences  are  due,  whether  to  differences  in  native 
endowment,  to  differences  in  training,  or  to  opportunity. 
In  this  sense  the  psychology  of  mental  types  or  of  in- 
dividual differences  is  yet  to  be  written. 


CHAPTER  XVH 
THE  SELF 

THE  last  problem,  the  nature  of  the  self,  the  *  I/  is 
fundamental.  Throughout  the  book,  we  have  been  ask- 
ing what  man  can  do  and  what  his  mental  processes  are 
and  what  they  mean.  Now  we  must  raise  the  more  gen- 
eral question,  what  is  it  that  makes  the  self,  and  how  is 
the  self  known  ?  Much  of  the  discussion  of  the  nature  of 
the  self  in  philosophy  and  in  popular  thought  and  con- 
versation has  little  to  do  with  psychology.  On  many  of 
these  problems  the  opinion  of  the  psychologist  is  little  if 
any  more  valuable  than  that  of  the  untrained  layman. 
Certain  phases  of  the  problem  of  the  self  are  of  a  psy- 
chological character,  however,  and  consideration  of  them 
is  not  only  important  for  itself,  but  serves  to  give  a  review 
in  perspective  of  many  of  the  more  concrete  discussions. 
Without  prejudice  to  the  problems  that  lie  beyond  the 
range  of  psychology,  we  speak  from  the  standpoint  of  the 
psychologist. 

The  Content  of  the  Idea  of  the  Self.  —  The  self  may  be 
approached  from  two  distinct  sides.  One  may  ask  what 
is  in  mind  when  one  thinks  '  I.'  This  question  is  on  the 
same  level  as  any  other  concerning  the  nature  of  a  mental 
state;  it  is  a  question  of  structure.  Questions  of  the 
other  type  deal  with  the  capabilities  of  the  man ;  they 
408 


THE   SELF  409 

ask  what  the  self  does  in  different  relations,  they  raise 
problems  of  function.  The  one  problem  is  of  what  the 
man  himself  appreciates  as  himself ;  the  other  asks  what 
it  is  that  makes  an  observer  regard  the  man  as  con- 
tinuously the  same  person,  why  he  is  trusted  to  act  in  a 
definite  way,  at  all  times.  The  problems  are  different, 
although  closely  related.  What  one  accomplishes  colours 
one's  idea  as  to  what  one  is,  and,  conversely,  what  one 
thinks  one's  self  to  be  has  a  considerable  effect  in  deter- 
mining what  one  can  accomplish.  For  our  purposes,  one 
is  the  problem  of  the  self  as  viewed  from  within,  the 
other  the  problem  of  the  self  as  it  presents  itself  to  the 
onlooker. 

The  idea  that  is  in  consciousness  when  one  thinks  '  I ' 
varies  from  moment  to  moment  and  from  individual  to 
individual.  It  has  been  suggested  that  it  is  made  up  in 
part  of  the  mirror  images  of  one's  self,  in  part  of  the 
framework  of  nose  and  eyebrows  through  which  one  views 
the  world,  and  of  the  constant  background  of  tactual  and 
organic  sensations.  Probably  some  of  these  elements 
may  be  present  in  the  idea  of  the  self,  and  each  has,  at 
some  time  or  other,  helped  to  make  the  individual  ac- 
quainted with  himself.  The  most  prominent  group  of 
elements  in  the  total  picture  is  the  mass  of  organic  sensa- 
tions. They  are  always  present,  although  they  vary  in 
quality,  and  probably  always  colour  the  mental  life. 
When  '  I '  feel  ill,  they  are  of  one  sort ;  when  '  I '  feel 
well,  they  are  of  another  character.  In  either  case,  ill- 
being  or  well-being  is  appreciated  through  them.  The 
importance  of  these  organic  sensations  has  been  em- 
phasised by  the  fact  that  in  certain  cases,  loss  of  appre- 


410  THE   ESSENTIALS   OF   PSYCHOLOGY 

ciation  of  self-identity  seems  to  depend  upon  a  trans- 
formation of  the  organic  sensations.  The  individual 
whose  permanent  sensations  have  undergone  a  change, 
no  longer  feels  himself.  It  seems  likely  when  a  patient 
in  delirium  seems  to  be  watching  himself  from  above  or 
from  somewhere  else  outside  of  his  body,  that  the  disease 
processes  have  changed  these  sensations,  and  the  man  no 
longer  recognises  himself.  These  sensations  constitute 
only  a  part  of  the  idea  of  the  self  regarded  as  content. 
One  must  add  the  social  elements  in  the  idea  that  are 
probably  even  more  important.  It  is  not  so  much  how 
one  actually  does  appear,  as  how  one  thinks  one  appears 
to  others  that  constitutes  the  notion  of  the  self.  In  this 
idea,  as  James  points  out,  a  large  place  is  taken  by  ex- 
ternal belongings,  clothing,  automobiles,  bank  account, 
and  possessions  of  all  sorts.  One  grows  with  one's  goods, 
and  even  with  one's  friends  and  the  circle  of  acquaint- 
ances. But  while  all  of  these  elements  serve  to  give  tone 
to  the  idea  of  the  self,  that  idea  itself  is  a  concept  devel- 
oped through  the  experience  of  'the  individual  to  repre- 
sent and,  in  part,  to  account  for  himself.  Like  all 
concepts,  the  content  may  vary  greatly;  but  the  thing 
represented  is  more  fixed,  although  that,  too,  is  subject 
to  constant  change  with  growth  and  with  the  phases  of 
experience  that  it  represents. 

The  Active  Self.  —  The  treatment  of  the  active  self 
offers  more  difficulties.  The  idea  of  the  self  as  an  agent 
has  developed  to  explain  the  unity  and  continuity  of 
conscious  processes  in  any  individual,  and  to  make  the 
consistency  of  the  different  acts  of  the  same  man  conceiv- 
able. If  consciousness  were  merely  a  mass  of  states,  an 


THE   SELF   AS  ACTIVE  411 

individual's  experience  would  not  be  regarded  as  con- 
tinuous, as  parts  of  a  single  whole,  but  would  be  a  mere 
jumble  of  separate  events  or  things.  Even  the  mental 
states  of  any  moment  would  be  only  separate  states, 
it  has  been  asserted,  unless  they  were  held  together  in 
some  way.  The  concept  of  the  self  has  been  developed 
popularly  and  philosophically  to  make  conceivable  the 
fact  that  mental  states  do  constitute  a  unity  and  that  all 
states  of  whatever  period  are  regarded  as  my  states. 
The  facts  implied  by  the  term  self  are  that  the  different 
experiences  are  parts  of  a  single  whole  which  persists 
from  life  to  death,  and  that  the  thoughts  of  any  moment 
constitute  a  unity.  More  practical  is  the  problem 
as  it  presents  itself  to  the  friend  or  business  associate. 
This  is,  why  does  the  same  man  act  in  approximately  the 
same  way  toward  the  same  situations,  and  why  are  his 
methods  of  action  peculiar  to  himself?  When  a  man 
makes  a  sudden  change  in  his  course  of  action,  it  is  at 
once  said  that  he  is  no  longer  himself.  The  facts  to 
be  explained  in  connection  with  the  self  are  first,  the 
continuity  of  conscious  states ;  second,  the  unity  of  con- 
sciousness at  any  moment ;  and  third,  the  self-consistency 
of  action. 

The  Self  as  Accumulated  Habits.  —  One  of  the  most 
superficial  explanations  of  the  consistency  of  action  from 
moment  to  moment  is  to  be  found  in  the  persistence  of 
habitual  responses.  In  considerable  degree,  it  is  possible 
to  read  character  from  the  face.  So  far  as  this  is  possible 
at  all,  it  is,  as  was  said  in  an  earlier  chapter,  because  the 
face  retains  the  imprint  of  the  earlier  expressions  of  emo- 
tions and  of  feelings.  Every  thought  and  feeling  induces 


412  THE   ESSENTIALS   OF   PSYCHOLOGY 

some  contraction  of  the  facial  muscles,  and  each  of  these 
contractions  leaves  its  impress  on  the  face  by  enlarging 
the  muscle  or  by  wrinkling  the  skin.  Thus  old  expres- 
sions and  indirectly  old  experiences  write  their  record  on 
the  face  for  him  who  runs  to  read.  But  these  same 
experiences  induce  habits,  not  merely  in  the  facial  mus- 
cles, but  in  all  parts  of  the  psycho-physical  organism ; 
in  consequence,  even  the  most  general  mental  and  physi- 
cal responses  and  attitudes  correspond  to  the  configu- 
ration of  the  face.  Both  have  been  developed  in  the 
same  way.  In  truth,  very  many  of  the  subtle  peculiari- 
ties, which  together  constitute  character,  are  traceable 
to  habits.  Much  of  good  temper  or  bad  temper  is 
dependent  upon  the  habit  of  smiling  or  of  scowling,  upon 
the  habit  of  sharp  speech  or  of  mild  speech.  Whether 
the  first  and  natural  attitude  toward  a  situation  is  of 
pleased  acquiescence  or  of  fault-finding  is  very  largely  a 
matter  of  habit.  Even  the  moral  elements  of  character 
have  their  habitual  constituents.  One  has  habits  of 
honesty  and  punctuality  in  meeting  obligations,  just 
as  one  has  habits  of  rising  or  of  eating.  It  is  as  diffi- 
cult to  break  a  habit  of  paying  bills  at  the  end  of  the 
month  as  a  habit  of  late  rising.  Bad  habits  in  morals 
may  reach  the  point  where  they  are  as  difficult  to  break 
as  a  drug  habit,  where  all  the  consequences  of  the  acts 
are  neglected.  At  this  stage,  the  man  has  become 
an  habitual  criminal,  and  self-restraint  must  give  way 
to  restraint  by  others.  A  self  of  one  sort  may  become 
altogether  changed  in  the  course  of  a  few  years,  merely 
through  the  development  of  a  new  set  of  habits.  The 
self  from  this  simple  point  of  view  is  in  great  part  merely 


THE   SELF   AND  EXPERIENCE  413 

the  accumulation  of  habits,  the  outcome  of  the  earlier 
actions  of  the  individual. 

The  Self  as  an  Expression  of  Organised  Experience.  — 
Still  more  intimately  connected  with  the  development 
of  the  self  and  self-control  is  the  effect  of  earlier  expe- 
riences as  they  are  expressed  in  present  experience. 
Throughout  our  treatment  of  the  earlier  topics,  particu- 
larly in  connection  with  reasoning  and  action,  we  have 
had  occasion  to  emphasise  the  importance  of  the  system 
of  knowledge  and  the  system  of  purposes.  It  has  been 
pointed  out  that  attention,  perception,  memory,  and 
action  in  all  of  its  higher  forms  are  controlled  by  earlier 
experiences,  not  as  single  and  sporadic  elements,  but  as 
organised  systems.  Practically  all  of  the  important 
functions  ascribed  to  the  self  are,  when  examined  criti- 
cally, seen  to  be  due  to  the  action  of  earlier  experience. 
What  makes  one  man  different  from  any  other  is  that 
he  sees  differently,  thinks  differently,  and  acts  differ- 
ently. These  depend  upon  the  actual  knowledge  that 
he  has  accumulated,  upon  the  associations  and  habits 
that  he  has  developed,  but,  above  and  beyond  that, 
upon  the  control  of  organised  knowledge  and  upon  de- 
veloped purposes.  The  individual  starts  life  with  cer- 
tain instincts  that  are  a  part  of  the  common  racial  in- 
heritance. The  early  self,  so  far  as  one  may  speak  of 
the  infant  as  having  a  self,  is  dependent  upon  these  in- 
stincts for  its  character.  As  he  grows,  these  are  first 
modified  by  experience,  then  experiences  become  the 
dominating  factors  hi  determining  the  nature  of  the  re- 
sponses, mental  and  physical.  There  is  seldom  a  com- 
plete and  sudden  change  in  the  character.  It  is  only 


414        THE  ESSENTIALS  OF  PSYCHOLOGY 

gradually  that  the  original  instinctive  character  is  modi- 
fied by  experience;  the  single  experiences  in  the  later 
stages  work  but  a  comparatively  slight  change.  The 
original  kernel  of  the  self  constantly  grows  and  expands 
by  taking  up  into  itself  new  bits  of  knowledge.  As 
Tennyson  sings  in  his  '  Ulysses/  '  I  am  a  part  of  all  that 
I  have  seen.'  Ordinarily  it  takes  years  to  make  a  marked 
difference.  The  self  of  to-day  is  not  noticeably  different 
from  the  self  of  yesterday,  although  it  is  markedly  dif- 
ferent from  the  self  of  twenty  years  ago.  Occasionally 
one  will  see  a  sudden  '  about-face  '  in  a  character.  In- 
stances of  sudden  conversion  may  be  cited.  Some  strik- 
ing event  seems  to  throw  new  light  on  the  relation  of  the 
individual  to  the  world  and  his  fellows,  and  his  entire 
attitude  changes,  and  with  that  his  actions.  Sometimes 
a  sudden  misfortune  will  destroy  the  confidence  built  up 
through  a  lifetime  of  successful  activity.  The  resolute, 
self  reliant  man  of  affairs  becomes  hesitant,  dependent, 
and  all  initiative  is  lost ;  he  becomes  a  human  derelict 
who  cannot  be  relied  upon  for  even  the  simplest  tasks. 
Such  sudden  changes  are  the  exception;  usually  char- 
acter is  of  slow  growth  and  the  changes  can  be  detected 
only  after  the  lapse  of  years.  The  individual  peculiari- 
ties and  the  consistency  of  action  that  mark  the  self 
depend  in  part  upon  the  habits,  and  in  part  upon  the 
control  exerted  by  the  accumulated  experiences  and 
purposes  upon  thought  and  action. 

The  Self  as  a  Continuous  Existence.  —  The  second 
function  or  characteristic  of  the  self  is  to  explain  the  fact 
that  all  mental  states  are  regarded  as  belonging  together. 
This  depends  in  part  at  least  upon  the  continuity  of 


THE   SELF  415 

memory.  Professor  James  has  asserted  that  what  makes 
the  self  continuous  is  that  one  mental  state  always 
laps  over  upon  the  next.  There  are  no  blank  spaces 
that  separate  one  process  from  another.  At  any  mo- 
ment, several  ideas  are  represented  at  different  stages 
of  development  or  disappearance.  Other  factors  are 
found  in  the  persistence  of  memories,  and  in  recogni- 
tion. The  self  probably  is  recognised  in  very  much 
the  same  way  as  any  object.  The  older  experiences 
interpret  the  new.  Recognition  of  objects,  as  well  as 
the  recognition  of  the  self,  serves  to  prove  the  contin- 
uous identity  of  the  train  of  experiences.  To  these 
must  be  added  the  fact  of  the  return  of  old  memories, 
and  the  anticipation  of  future  events  in  the  light  of  the 
past.  When  these  anticipations  are  confirmed  by 
actual  experiences,  the  new  is  more  firmly  bound  to  the 
old  and  the  old  to  the  new.  That  one  is  constantly 
looking  forward  and  backward  from  the  present  and, 
particularly,  that  the  past  anticipations  are  confirmed 
by  the  events  of  the  present,  serve  to  bind  past,  present, 
and  future  into  a  single  whole.  The  continuity  of 
reference,  the  development  of  types  and  meanings, 
and  the  confirmation  or  partial  modification  of  the 
meaning  of  one  time  by  the  meaning  of  the  next,  all  con- 
tribute their  share  to  establishing  the  belief  that  the 
self  persists. 

'  The  Self  as  the  Unity  of  Experience.  —  To  say  that  the 
self  of  any  moment  is  a  unit  means  merely  that  the  com- 
ponent elements,  in  addition  to  being  controlled  and  sub- 
ordinated to  the  whole,  must  all  be  connected,  and  each 
must  add  its  share  to  the  whole.  As  was  said  in  the 


416         THE  ESSENTIALS  OF  PSYCHOLOGY 

second  chapter,  the  consciousness  of  any  moment  cor- 
responds to  the  action  of  many  different  nerve  units  in 
many  different  parts  of  the  cortex,  but  to  be  conscious, 
any  one  of  these  elements  must  be  connected  with  all 
of  the  others  active  at  the  time.  To  be  conscious 
and  to  belong  to  the  unity  of  the  self  are  synonymous. 
This  mass  of  mental  states  not  only  belongs  together, 
but  acts  as  a  unit  in  the  control  of  all  subordinate  mental 
activities.  No  experience  is  ever  of  discrete  units,  nor 
is  any  single  process  alone  effective  in  determining  the 
course  of  mental  or  physical  activity.  This  intercon- 
nection, at  once  passive  and  active,  is  the  basis  of  the 
unity  of  the  self  at  any  moment.  One  often  speaks  of 
the  unconscious  or  the  subconscious,  as  if  there  were  a 
consciousness  detached  from  the  main  or  dominant  con- 
sciousness, separated  from  the  unity  that  has  just  been 
mentioned.  It  is  true  that  movements  are  often  made 
without  consciousness,  and  still  seem  to  be  controlled  by 
purposes.  There  are  other  instances  in  which  all  or  part 
of  a  course  of  thought  shows  characteristics  of  purpose 
that  might  have  been  developed  by  conscious  states,  but 
in  which  there  is  no  evidence  of  consciousness.  In  all  of 
these  cases  it  is  probably  safer  to  assume  that  the  deter- 
minants are  physiological  or  nervous,  rather  than  con- 
scious. Surely  the  only  safe  evidence  of  consciousness  is 
consciousness  itself.  An  unconscious  conscious  state  is 
a  contradiction  in  terms. 

Dissociated  Selves.  —  The  consistency  of  thought  and 
act  that  marks  the  man  as  peculiarly  himself,  the  persist- 
ence of  self-appreciation  from  day  to  day,  and  the  mo- 
mentary unity  of  experience,  each  goes  back  for  its  explana- 


ALTERNATING   SELVES  417 

tion  to  the  fact  that  all  the  accumulated  experiences  of 
the  individual  are  combined  into  a  single  whole  through 
the  manifold  interconnections  of  the  parts.  These  inter- 
connections give  meaning  to  the  different  parts,  and 
serve  to  direct  and  coordinate  the  various  activities. 
That  these  relations  and  factors  are  actual,  not  hypo- 
thetical, is  demonstrated  by  the  numerous  cases  of  dis- 
sociation of  the  self,  in  which  the  continuity  of  thought 
and  action  is  broken.  An  individual  who  is  dominated 
at  certain  times  by  one  set  of  purposes  and  ideals  will,  at 
other  times,  be  dominated  by  other  purposes  and  ideals. 
At  the  instant  of  change,  there  will  also  be  a  break  in  the 
continuity  of  memory,  and  a  transformation  in  the  atti- 
tude toward  conventional  and  moral  restraints.  The 
individual  will  carry  on  the  ordinary  routine  life  until 
some  emotional  shock  or  injury  is  suffered.  Then 
all  memory  of  the  past  will  be  lost ;  he  will  start  up  with 
no  remembrance  of  his  surroundings;  in  some  cases, 
with  no  appreciation  of  any  of  the  things  about,  and 
none  of  his  accumulated  knowledge.  In  many  cases, 
the  selves  alternate.  One  self  with  its  peculiar  mem- 
ories and  characteristic  actions  and  feelings  will  be 
dominant  for  a  time,  and  the  individual  will  have  one 
set  of  memories,  one  emotional  attitude  toward  the  world  ; 
then  suddenly  the  other  will  get  the  upper  hand,  all 
memories  acquired  by  the  earlier  self  will  be  forgotten, 
and  the  entire  character  of  the  individual  will  change. 
One  of  the  earlier  cases  reported  was  of  a  woman,  Felida 
X,  who  in  the  one  self  vas  moody  and  bad  tempered ; 
when  the  other  self  came,  she  would  be  cheerful,  a  more 
capable  worker,  and  different  in  every  respect  from  the 


418        THE  ESSENTIALS  OF  PSYCHOLOGY 

first.  These  states  alternated  for  a  period  of  thirty  years 
or  more.  They  would  be  separated  by  a  period  of  uncon- 
sciousness at  times,  and  at  times  the  change  from  one  to 
the  other  would  be  sudden  and  with  but  slight  warning. 
After  the  change,  the  immediately  preceding  events 
would  not  be  remembered.  Later,  when  Felida  had 
come  to  know  the  symptoms  of  the  change,  she  would 
write  down  the  things  she  would  need  to  know  in  the 
approaching  state.  She  was  a  small  shopkeeper,  and 
if  she  felt  the  change  coming  in  the  midst  of  a  sale,  she 
would  record  the  amount  of  the  purchase  or  of  the 
money  that  she  had  received  that  she  might  continue 
the  transaction  without  mistake  when  the  new  self 
appeared. 

The  Nature  of  Dissociation.  —  So  far  as  present  knowl- 
edge extends,  it  seems  that  the  cause  of  the  dissocia- 
tion of  the  self  is  to  be  found  in  a  disturbance 
of  the  connections  between  the  experiences.  An 
emotional  shock  breaks  the  associations  between 
groups  of  cells,  or  cells  that  correspond  to  groups  of 
memories.  After  the  shock,  an  event  in  one  group  will 
recall  other  members  of  that  group  alone ;  the  recall  will 
not  extend  to  the  memories  dependent  upon  the  other 
group.  Also  and  more  important  for  the  explanation  of 
the  active  self,  the  acts  and  thoughts  and  emotions  will 
be  controlled  at  any  moment  by  the  experiences  that 
belong  to  one  group ;  elements  from  the  other  group  will 
have  no  effect  upon  action  at  the  times  the  other  group 
is  dominant.  The  acts  of  the  one  self,  or  group  of  ex- 
periences, will  be  consistent,  but  the  acts  of  one  self  will 
not  be  consistent  with  the  acts  of  the  other  self,  or  group 


DISSOCIATION   OF   THE   SELF  419 

of  experiences.  When  the  connections  between  differ- 
ent experiences  are  broken,  the  disappearance  or  the 
modification  of  qualities  ordinarily  attributed  to  the 
self  is  strong  proof  that  the  self  hi  the  normal  individual 
is  largely  determined  in  its  character  by  the  way  the  dif- 
ferent experiences  interact.  This  series  of  connections 
gives  continuous  memory,  makes  the  experiences  of  any 
moment  a  unit,  and  through  directing  thought  and  act 
keeps  the  self  of  one  moment  consistent  with  the  self  of 
other  moments. 

Minor  Forms  of  Dissociation.  —  Slighter  signs  of 
alternating  selves  may  be  found  in  normal  individuals. 
The  hypnotic  condition  differs  from  the  -normal  very 
much  as  one  of  the  dissociated  selves  differs  from  another ; 
and  selves  may  be  induced  in  the  hypnotic  state  that 
are  related  in  every  practical  respect,  as  are  the  disso- 
ciated or  alternating  selves.  In  the  normal  state  one 
seldom  has  memories  of  the  hypnotic  state,  and  by 
suggestion  during  hypnotism  it  is  easy  to  change  the 
character  of  the  self,  practically  at  will.  Similar  normal 
divisions  in  the  self  may  be  seen  in  the  life  of  any  indi- 
vidual. The  ordinary  business  man  is  one  man  at 
home,  and  another  in  his  place  of  business.  He  thinks 
differently,  and  acts  differently.  Of  course  here  the 
dissociation  is  restricted  to  the  control  of  action ;  mem- 
ory is  continuous,  and  the  actions  are  not  sufficiently 
different  to  prevent  the  man  from  being  recognised  as 
himself.  It  is  very  interesting  to  note  that  various 
groups  of  responses  are  aroused  on  relatively  slight 
suggestions.  Frequently  men  undergo  el'"  ages  as  they 
change  their  surroundings.  A  man  mav  be  perfectly 


420       THE  ESSENTIALS  OF  PSYCHOLOGY 

at  his  ease  in  his  own  home,  and  very  much  embarrassed 
or  very  diffident  when  in  a  strange  place.  Clothing 
frequently  plays  a  considerable  part  in  suggesting  selves 
or  groups  of  responses.  All  one's  self-possession  may 
be  destroyed  if  one  finds  one's  self  in  company  without 
some  usual  article  of  apparel,  a  cravat,  for  example. 
Manners  frequently  are  put  on  with  the  garments.  It 
is  said  of  Stanley,  the  African  explorer,  that  his  ability 
to  make  a  speech  depended  upon  his  wearing  a  small 
cap  that  had  been  given  him  by  Livingstone.  When 
called  upon  to  reply  to  a  toast,  or  when  lecturing,  he 
invariably  donned  this  cap.  Without  it,  he  seemed 
tongue-tied.  Many  lecturers  feel  lost  without  a  read- 
ing desk  even  if  they  never  use  notes,  and  the  absence 
of  some  familiar  article  of  furniture  may  destroy  their 
composure.  In  each  of  these  cases,  the  familiar  situation 
or  the  familiar  article  arouses  a  group  of  experiences 
that  will  not  be  present  without  it.  The  actions  grow 
out  of  the  experiences.  When  all  of  the  usual  accom- 
paniments are  present,  the  course  of  thought  and  speech 
or  act  runs  smoothly ;  without  some  apparently  insig- 
nificant element,  the  whole  complex  is  disturbed. 

The  Self  a  Social  Product.  —  One  is  aware  of  the 
character  of  the  effective  self  altogether  through  the 
social  relations.  Were  it  possible  for  a  child  to  grow  up 
alone,  he  would  have  no  appreciation  of  his  character. 
He  would  not  know  whether  he  were  quick-tempered 
or  slow  to  anger,  whether  he  were  honest  or  dishonest, 
strong  or  weak.  The  questions  that  grow  out  of  the  self 
problem  would  not  occur  to  him.  All  of  these  character- 
istics of  the  self  are  appreciated  only  when  there  is  a 


THE   SELF   AND   SOCIETY  421 

chance  to  compare  himself  with  others.  He  knows  him- 
self only  as  he  sees  himself  reflected  in  the  opinions  of 
others.  This  statement  is  the  converse  of  the  other  state- 
ment, that  man  knows  others  or  at  least  the  mental 
processes  of  others  only  in  so  far  as  he  can  interpret  their 
acts  in  terms  of  his  own  conscious  states.  The  processes 
of  knowing  one's  self  and  of  knowing  others  are  correla- 
tive. Each  can  be  known  and  appreciated  only  in  the 
light  of  the  other.  One  passes  judgment  on  the  acts  of 
others  and  then  compares  his  own  acts  with  them,  to 
obtain  the  judgment  of  himself  and  others  upon  himself. 
What  is  constantly  dominant  in  the  idea  of  the  self 
is  the  impression  that  others  have.  One  holds  one's 
self  at  the  estimate  others  have  or  are  imagined  to  have. 
The  Self  a  Concept.  —  For  psychology,  the  notion  of 
the  self  is  a  concept  similar  in  origin  and  development 
to  any  other.  The  elements  about  which  the  concept 
centres  are  the  organic  and  other  persistent  sensations. 
These  elements  are  closely  connected  with  the  original 
egoistic  instincts  and  receive  constant  additions  by  the 
development  of  new  ideas  and  new  habits.  The  concept 
probably  always  represents  activities  rather  than  mental 
states.  In  its  developed  form  it  is  the  representative 
in  thought  of  the  continuity  of  consciousness,  of  the 
fact  that  the  different  experiences  all  belong  to  the 
same  individual,  and  that  the  acts  of  the  individual  are 
consistent  at  all  times.  The  occasion  for  the  develop- 
ment of  the  concept  is  largely  social,  as  the  need  for 
the  idea  is  social.  Society  must  know  to  what  extent  an 
individual  is  to  be  relied  upon  and  how  he  will  act  in  all 
respects  in  any  set  of  circumstances.  The  self  is  society's 


422        THE  ESSENTIALS  OF  PSYCHOLOGY 

way  of  formulating  this  knowledge.  It  is  important,  too, 
that  the  individual  should  know  how  he  is  regarded,  and 
for  his  own  benefit  should  know  what  he  is  likely  to  do 
in  any  situation.  These  needs  have  led  to  the  develop- 
ment of  the  notion  of  the  self  with  all  that  it  implies. 

Thus  for  psychology  the  self  is  a  concept  to  be  traced 
to  its  sources,  —  is  one  phenomenon  among  others  to  be 
explained  as  best  we  may,  but  such  a  treatment  will 
never  be  satisfactory  for  any  one  else.  What  for  the 
psychologist  is  just  one  problem  on  the  same  level  as  any 
other,  is  for  the  layman  or  for  any  one  in  a  non-psycho- 
logical attitude  the  very  core  of  his  being.  From  it  ir- 
radiate all  desires,  its  advancement  is  the  goal  of  all 
egoistic  instincts,  it  is  the  centre  of  nearly  all  our  joys 
and  sorrows.  To  it  are  referred  all  of  our  purposes  in 
life,  its  exaltation  is  the  object  of  most  of  our  activity. 
All  social  and  physical  events  are  measured  by  their 
effects  on  our  personal  ambition  and  personal  welfare. 
As  the  occasion  of  solicitude  in  all  of  our  social  and 
religious  aspirations,  the  self  takes  on  a  value  that  makes 
any  scientific  analysis  seem  entirely  inadequate  and  even 
presumptuous.  The  treatment  of  the  psychologist  grows 
out  of  his  peculiar  methods  and  needs,  and  much  still 
remains  to  be  done  even  to  attain  his  end  in  his  own  way. 
The  answers  it  gives  must  be  unsatisfactory  to  the  popu- 
lar mind,  for  the  problems  that  most  interest  it  lie  far 
afield  for  the  psychologist.  They  can  be  approached  to 
advantage  only  by  the  methods  and  on  the  assumptions 
of  ethics,  metaphysics,  and  religion.  On  these  problems 
psychology  has  nothing  to  say,  since  the  limitations  of  its 
methods  and  its  knowledge  give  it  no  right  to  an  opinion. 


THE   SELF  423 

QUESTIONS 

1.  Under  what  circumstances  and  for  what  end  does  the  idea  of 
self  develop  ? 

2.  Would  you  have  your  present  idea  of  self  if  you  had  chanced 
to  survive  alone  on  a  desert  island  ? 

3 .  What  do  you  have  in  mind  as  you  think '  I '  (a)  when  striving 
to  win  in  a  wrestling  match?  (b)  when  you  think  of  a  rival  for  a 
class  honor?   (c)  when  conversing  in  a  congenial  group? 

4.  What  is  the  relation  of  the  'self  to  the  other  psychological 
processes?   to  will?   to  emotion?  to  attention?    Are  they  whole 
and  part  or  independent  partners? 

5.  What  gives  consistency  to  the  actions  ?    What  do  you  mean 
when  you  say  you  were  not  yourself  in  a  certain  emergency? 

6.  What  do  you  mean  by  continuous  self -identity?    What 
makes  it  possible? 

7.  How  are  these  last  two  functions  disturbed  in  a  dissociated 
personality  ? 

8.  Is  it  more  nearly  true  to  say  that  for  modern  psychology 
there  is  no  self  or  that  man  is  all  self? 

REFERENCES 

JAMES  :  Principles  of  Psychology,  vol.  i,  chs.  ix  and  x. 
COOLEY  :  Human  Nature  and  the  Social  Order. 
ANGELL  :  Psychology,  ch.  xxiii. 
PRINCE  :  The  Dissociation  of  a  Personality. 
MOLL:  Hypnotism. 


INDEX 


Abnormal  psychology,  14. 
Accommodation  in  the  perception  of 
depth,  181. 

mechanism  of,  90  f . 
Action,  326-357. 

Adrenal  secretion  in  emotion,  300  f. 
Affection,  204  f . 
After-images,  97. 
Agraphia,  44. 
Alexk,  43  f. 
Analogy,  263  f. 
Analysis,  114  f. 
Angell,  F.,  382. 
Angell,  J.  R.,  63, 140, 266, 303, 325,  387, 

423- 

Aphasia,  43  ff . 
Aristotle,  17,  142,  147. 
Association,  146-158. 

a  form  of  habit,  61  f. 

control  of,  152-157. 

in  perception,  170  f. 

laws  of,  147  ff. 
Association  areas,  41  f. 
Attention,  112—139. 

and  association,  154  ff. 

conditions  of,  115-125. 

duration  of,  131. 

genesis  of,  136  f. 

nervous  basis  of,  124  f. 

range  of,  132  f. 

Attitude,  a  condition  of  attention,!  18  f. 
Auditory  perception  of  space,  188  f. 
Axone,  27  ff. 

sheaths  of,  27  f. 

Bair,  357. 
Behaviour,  4  f . 

psychology  science  of,  i  f . 
Belief,  244. 
Binet,  403. 
Binet  scale,  400  f. 


Biological  theory  of  instinct,  270  ff. 
Biology  and  psychology,  n. 
Brain  and  mind,  defects  of,  19. 
Brain  stem,  36  f. 
Bryan,  336. 

Cannon,  308  f .,  325. 
Centrally  aroused  sensations,  qualities 
of,  158-160. 

in  perception,  170  f. 
Choice,  346-352. 
Clearness,  114. 

Coefficient  of  correlation,  390  f. 
Colour  blindness,  97. 
Colour  contrast,  98  f . 
Colours,  complementary,  96  f. 

primary,  94  f . 
Concept,  245-254. 

self  as,  421  f. 
Consciousness  and  behaviour,  4  ff. 

and  the  nervous  system,  17  ff. 

definition  of,  6. 

elements  of,  65. 

Control  of  ideas,  nervous  basis  of,  157  f. 
Convergence,  a  factor  in  the  percep- 
tion of  depth,  181. 
Cooley,  423. 
Coover,  382. 
Cord,  action  of,  32  ff. 

paths  in,  34  f. 
Cortex,  action  of,  37  ff. 
Cramming,  225. 
Cutaneous  sense-organs,  73  f. 

Darwin,  312  f. 

Dearborn,  380. 

Deduction,  260  f. 

Definition  of  psychology,  i  ff. 

Dendrite,  25  f. 

Depth,  perception  of,  180-186. 

Descartes,  313. 


425 


426 


INDEX 


Dewey,  266,  300,  305. 
Dissociated  selves,  416  ff. 
Distance,  perception  of,  179  f. 
Distraction  and  attention,  134  S. 
Distribution  of  intelligence,  390  ff. 
Double  images  in  perception  of  depth 

182  f. 

Dreams,  371  f. 
Duty,  a  condition  of  attention,  122  f. 

Ear,  structure  of,  80  ff. 

Ebbinghaus,  214  f.,  224. 

Ebert,  380  f. 

Economics  and  psychology,  12. 

Eder,  316. 

Education,  a  condition  of  attention, 

121  f. 

and  psychology,  12  f. 
Effort,  126. 
Ellis,  371. 
Emotion,  304-325. 
Evaluation,  judgment  as,  257  f. 
Experience,  6  f . 
Experiment,  8  f . 
Experimental  psychology,  15. 
Eye,  structure  of,  88  ff. 

Faculty  psychology,  criticism  of,  374. 
Fatigue,  358-368. 
Fechner,  14. 

Feeble-mindedness,  402  f. 
Feeling,  288-303. 

theories  of,  298-302. 
Forgetting,  214-218. 
Freud,  316,  318,  371. 
v.  Frey,  71. 

Gallon,  164. 
Ganglion,  23. 
Genetic  psychology,  14. 
Genius,  403  ff . 
Grey  matter,  23. 

Habits,  56-63. 

and  instinct,  280  f. 

and  the  self,  411  f. 
Hallucination,  200. 
Harter,  336. 
Haze,  influence  of,  on  perception,  184. 


Hearing,  70-87. 

theories  of,  83  ff. 
H*k,  387. 
Helmholtz,  171. 

Helmholtz  theory  of  hearing,  83  ff. 
Ilaredity  and  attention,  123. 
History  in  relation  to  psychology,  12. 
Hodge,  360. 
Ho  well,  48,  in. 
Hypnotism,  419. 

Ideals  as  motives,  347  ff. 
Illusion,  general,  199  f. 

optical,  196-199. 
Imagination,  236  f. 
Imitation,  280. 
Impulse  and  emotion,  311  f. 
Inattention,  133  f. 
Induction,  262  f. 
Inference,  259. 
Inhibition,  associative,  213  f. 

reproductive,  221  f. 

retroactive,  215  f. 
Instinct*  267-287. 

and  emotion,  306  ff. 

and  the  synapse,  269. 
Intellect  and  emotion,  320  ff. 
Intelligence  and  character,  392  ff. 

general,  training  of,  383. 
Intensity,    a    condition    of    attention, 

115  ff. 

Interest,  125. 
Interrelations    of    mental    functions, 

374-387- 

Introspection,  7  f. 
Introspective  psychology,  15. 

James,  63,  140,  240,  273,  287,  306,  308, 

325.  345,  379,  415,  423- 
James's  theory  of  emotion,  306  ff. 
Jastrow,  170  f.,  175,  325. 
Jones,  Ernest,  373. 
Judd,  63,  373,  387. 
Judgment,  256-259. 

Kinaesthetic  sensations.  101  L 
Kiilpe,  159. 

Lange,  306. 
Learning,  209-214. 


INDEX 


4*7 


as    selection    of   instinctive    move- 
ments, 330  f . 

rules  for,  234  ff. 
Lipps,  301. 
Livingstone,  420. 
Local  sign,  177  ff. 
Localisation     of     cortical     functions, 

40  ff. 
Locke,  65. 

MacDougall,  305. 
Marshall,  303. 
Meaning,  245  ff. 
Meissner,  73. 
Memory,  204—236. 

logical,  222  ff. 

seat  of,  143. 

systems,  231  ff. 

training  of,  379  ff. 

types,  161-165. 
Mental  process,  6  ff. 
Mental  tests,  399. 
Meumann,  240,  380  f. 
Midbrain,  action  of,  37. 
Mind  and  body,  relation  of,  50  f . 

and  brain,  relation  of,  17  ff. 

definition  of,  6  f. 
Moll,  423- 
Mood,  322  f. 
Morgan,  J.  B.,  135,  140. 
Morgan,  Lloyd,  243,  272,  287. 
Mosso,  359. 

Motion,  a  factor  in  perception  of  dis- 
tance, 184. 

perception  of,  186  f. 
Motor  accompaniments  of  attention, 

127  ff. 
Movements,  control  of,  338-344. 

in  perception  of  distance,  179  f. 
M  tiller,  Johannes,  66. 
Myers,  373. 

Nervous  impulse,  transmission  of,  28  ff . 
Nervous     system,     development     of, 
19  ff. 

divisions  of,  21  ff. 

embryonic  development  of,  24  f. 
Neurones,  25  ff. 

connections  of,  31  ff. 
Noise,  85  f. 


Observation,  7. 

Observational  memory,  206  ff. 
Offner,  373. 
Organic  sensations,  103  f. 

Pain,  73- 
Paramnesia,  231. 
Pawlow,  319. 
Perception,  169-203. 

of  time,  190  f. 

Perseveration  tendency,  146. 
Perspective,  184. 
Physiological  psychology,  14. 
Plato,  231. 
Play,  279  f. 
Pleasure  and  displeasure  as  feelings, 

291. 

Position,  perception  of,  177  ff. 
Pressure,  71  f. 
Prince,  320,  423. 

Projection  of  memory  Juiages,  160  f. 
Proof,  260-264. 
Psychophysics,  14. 
Purpose,    a    condition   of    attention, 

119  ff. 

Quain,  48. 

Rational  psychology,  »5. 

Reading,  as  illustration  of  perception, 

192  f. 
Reasoning,  241-266. 

stages  of,  254  f. 
Recall,  218-222. 
Recognition,  227—231. 
Reflex  and  instinct  distinguished,  282  f. 
Repression  of  emotion,  316. 
Rest,  best  period  for,  363. 
Retention,  142-146,  214-218. 

and  habit,  144  f. 
Retina,  function  of,  91  ff. 
Rivers,  316. 
Royce,  387. 

Seashore,  in,  140,  168,  aoj. 
Self,  the,  408-423. 
Self-control,  317  f. 
Sensation,  64-111. 

and  feeling,  292  f.1 

development  of,  67  f. 


428 


INDEX 


Sensations  centrally  aroused,  158  ff. 

of  temperature,  68  f. 
Shadows    in    perception    of     depth, 

185. 

Shepard,  373. 
Sherrington,  54. 
Skill,  acquisition  of,  333  ff. 
Sleep,  368-370. 
Smell,  77  f. 

Social  determinants  of  attention,  122  f. 
Social  instincts,  277!. 
Sociology  and  psychology,  12. 
Space,  perception  of,  176-186. 
Spearman,  383. 
Specific    energy    of    sensory    organs, 

66  f. 

Speech,  action  of  cortex  in,  42  t 
Stanley,  420. 
Static  sense,  102  f. 
Stereoscopic  illusion  of  depth,  183. 
Stout,  300,  303. 

Superposition,  a  factor  in  depth  per- 
ception, 185. 
Swift,  334- 
Syllogism,  260  f. 
Synapse,  35  ff .,  52  ff. 

action  of,  35  f . 
Synthesis,  114  £. 


Taste,  sensations  of,  74  ff. 

Temperament,  323  f. 

Temperature  scale,  70  f . 

Tennyson,  414. 

Testimony,  fidelity  of,  206. 

Thorndike,  387. 

Titchener,  140,  240,  266,  303,  325. 

Training,  transfer  of,  375-384. 

Trial  and  error  in  the  development  o? 

perception,  172  ff. 
as  method  of  learning,  329-331. 
Types  of  mind,  388-407. 

Visual  sensations,  87-101. 

Wang,  382,  387. 

Watson,  287. 

Watt,  240. 

Webb,  394. 

Weber's  law,  105  ff. 

Weissman,  270. 

Whipple,  391,  404. 

White  matter,  23. 

Will,  345-355. 

Work  and  fatigue,  359-368. 

Wundt,  300,  324. 


Zwaardemaker,  78  f. 


Printed  in  the  United  States  of  America. 


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